{"id":7317,"date":"2024-01-02T11:03:00","date_gmt":"2024-01-02T05:33:00","guid":{"rendered":"https:\/\/wordpress-505192-1602719.cloudwaysapps.com\/?p=7317"},"modified":"2024-01-02T17:08:28","modified_gmt":"2024-01-02T11:38:28","slug":"samacheer-kalvi-7th-science-term-3-chapter-1","status":"publish","type":"post","link":"https:\/\/samacheerguru.com\/samacheer-kalvi-7th-science-term-3-chapter-1\/","title":{"rendered":"Samacheer Kalvi 7th Science Solutions Term 3 Chapter 1 Light"},"content":{"rendered":"

Students can Download Science Chapter 1 Light Questions and Answers, Notes Pdf, Samacheer Kalvi 7th Science Book Solutions<\/a> Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.<\/p>\n

Tamilnadu Samacheer Kalvi 7th Science Solutions Term 3 Chapter 1 Light<\/h2>\n

Samacheer Kalvi 7th Science Light Textual Evaluation<\/h3>\n

I. Choose the correct option:<\/span><\/p>\n

Question 1.
\nLight travels only in a ______ .It is because of this property that.
\n(a) curved line, shadows
\n(b) straight line, shadows
\n(c) straight line, reflection
\n(d) curved line and then straight line, shadows
\nAnswer:
\n(b) straight line, shadows<\/p>\n

\"SamacheerKalvi.Guru\"<\/p>\n

Question 2.
\nLight that hits a mirror gets ______
\n(a) Transmitted
\n(b) Reflected
\n(c) Absorbed
\n(d) Refracted
\nAnswer:
\n(b) Reflected<\/p>\n

Question 3.
\n______ surface reflects the light well
\n(a) Water
\n(b) Compact disc
\n(c) Mirror
\n(d) Stone
\nAnswer:
\n(c) Mirror<\/p>\n

Question 4.
\nLight is a form of ____
\n(a) matter
\n(b) energy
\n(c) medium
\n(d) partical
\nAnswer:
\n(b) energy<\/p>\n

\"SamacheerKalvi.Guru\"<\/p>\n

Question 5.
\nYou can see your image in polished floors, but not in wooden table because ______
\n(a) regular reflection takes place in wooden table and irregular reflection in polished floor
\n(b) regular reflection takes place in polished floor and irregular reflection in wooden table
\n(c) regular reflection takes place in both polished floor and wooden table
\n(d) irregular reflection takes place in both polished floor and wooden table
\nAnswer:
\n(b) regular reflection takes place in polished floor and irregular reflection in wooden table<\/p>\n

Question 6.
\nChoose the translucent substance from the following
\n(a) glass
\n(b) wood
\n(c) water
\n(d) Clouds
\nAnswer:
\n(d) clouds<\/p>\n

Question 7.
\nReflection occurs , when the light
\n(a) about to reach a surface
\n(b) approaches a surface
\n(c) passes through a surface
\n(d) None Of these
\nAnswer:
\n(b) approaches a surface<\/p>\n

Question 8.
\nWhich of the following is the best reflector
\n(a) plastic plate
\n(b) plane mirror
\n(c) wall
\n(d) paper
\nAnswer:
\n(b) plane mirror<\/p>\n

Question 9.
\nSivarajan placed a meter stick in the playground at 7.00 am in the morning. How will the shadow of the stick at noon look in comparison to the one in the morning
\n(a) There will be no shadow
\n(b) The shadow will be longer and on the opposite side as the sun
\n(c) The shadow will be shorter and on the same side as the sun
\n(d) The shadow will be shorter
\nAnswer:
\n(d) The shadow will be shorter<\/p>\n

Question 10.
\nThe image formed by a pinhole camera is inverted because,
\n(a) light travels in straight lines
\n(b) light rays become laterally inverted as they pass through a pinhole camera
\n(c) light rays pass through the pinhole
\n(d) light rays get reflected
\nAnswer:
\n(a) light travels in straight lines<\/p>\n

Question 11.
\nWhich of the following facts explain how shadows are formed?
\n(a) Light travels in straight lines
\n(b) Opaque bodies do not allow light to pass through them
\n(c) Reflection occurs at a smooth surfaces like mirrors
\n(d) Lateral inversion happens
\n(a) both A and B
\n(b) both A and D
\n(c) both B and C
\n(d) only A
\nAnswer:
\n(a) both A and B<\/p>\n

\"SamacheerKalvi.Guru\"<\/p>\n

II. Fill in the blanks:<\/span><\/p>\n

    \n
  1. A plane mirror produces a _________ image<\/li>\n
  2. A _________ reflection helps us to see the objects.<\/li>\n
  3. The light ray gets _________ when it falls on any polisher surface<\/li>\n
  4. Sunlight is a blend of _________ colours<\/li>\n
  5. The splitting of white light into seven colours is called _________<\/li>\n
  6. The moon _________ sun light.<\/li>\n
  7. The sunlight can be split into its constituent colours using _________<\/li>\n
  8. Reflection of light from rough surface is called _________ reflection<\/li>\n<\/ol>\n

    Answer:<\/p>\n

      \n
    1. virtual and erect<\/li>\n
    2. regular<\/li>\n
    3. reflected<\/li>\n
    4. seven<\/li>\n
    5. dispersion<\/li>\n
    6. reflects<\/li>\n
    7. prism<\/li>\n
    8. irregular<\/li>\n<\/ol>\n

      III. Say TRUE or FALSE.<\/span><\/p>\n

      Question 1.
      \nThe image of right hand in a plane mirror looks like a left hand.
      \nAnswer:
      \nTrue<\/p>\n

      Question 2.
      \nRainbow is formed by dispersion of which light by water drops.
      \nAnswer:
      \nTrue<\/p>\n

      Question 3.
      \nThe image formed by the plane mirror is laterally inverted, hence the image seen through the periscope is also laterally inverted
      \nAnswer:
      \nFalse
      \nCorrect statement: The image formed by the plane mirror is laterally inverted, hence the image seen through the periscope is This is because in periscope, image is reflected by two mirrors.<\/p>\n

      \"SamacheerKalvi.Guru\"<\/p>\n

      Question 4.
      \nWe see planets because they reflect light from the sun
      \nAnswer:
      \nTrue<\/p>\n

      Question 5.
      \nWe see a book because it reflects the light that falls on its surface
      \nAnswer:
      \nTrue<\/p>\n

      Question 6.
      \nThe image formed in a pinhole camera is always inverted
      \nAnswer:
      \nTrue<\/p>\n

      Question 7.
      \nThe image formed in a pinhole camera is always the satne size as the object
      \nAnswer:
      \nFalse<\/p>\n

      \"SamacheerKalvi.Guru\"<\/p>\n

      Question 8.
      \nThe image formed in a plane mirror is upside down
      \nAnswer:
      \nFalse
      \nCorrect statement: The image formed in a plane mirror is erect.<\/p>\n

      Question 9.
      \nA plane mirror is opaque Ans.
      \nAnswer:
      \nTrue<\/p>\n

      Question 10.
      \nA shadow is formed on the same side of the object as the source of light.
      \nAnswer:
      \nFalse
      \nCorrect statement: A shadow is formed on the side of the object as the source of light.<\/p>\n

      Question 11.
      \nWe are able to see things around us with the help of regular reflection
      \nAnswer:
      \nTrue<\/p>\n

      \"SamacheerKalvi.Guru\"<\/p>\n

      Question 12.
      \nAfter passing through a prism, white light splits into a band of seven colours
      \nAnswer:
      \nTrue<\/p>\n

      IV. Match the following<\/span><\/p>\n\n\n\n\n\n\n\n\n\n\n
      1.<\/td>\nRectilinear propagation<\/td>\nPrimary source of light<\/td>\n<\/tr>\n
      2.<\/td>\nRectilinear propagation<\/td>\nNon-luminous object<\/td>\n<\/tr>\n
      3.<\/td>\nPlane Mirror Fire fly<\/td>\nPeriscope<\/td>\n<\/tr>\n
      4.<\/td>\nThe Moon<\/td>\nPinhole camera<\/td>\n<\/tr>\n
      5.<\/td>\nWide light source<\/td>\nSpectrum of light<\/td>\n<\/tr>\n
      6.<\/td>\nRegular reflection<\/td>\nluminous object<\/td>\n<\/tr>\n
      7.<\/td>\nThe sun<\/td>\nPenumbra<\/td>\n<\/tr>\n
      8.<\/td>\nBand of seven colors<\/td>\nGlossy surface<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

      Answer:<\/p>\n\n\n\n\n\n\n\n\n\n\n
      1.<\/td>\nRectilinear propagation<\/td>\nPinhole camera<\/td>\n<\/tr>\n
      2.<\/td>\nRectilinear propagation<\/td>\nPeriscope<\/td>\n<\/tr>\n
      3.<\/td>\nPlane Mirror Fire fly<\/td>\nluminous object<\/td>\n<\/tr>\n
      4.<\/td>\nThe Moon<\/td>\nNon-luminous object<\/td>\n<\/tr>\n
      5.<\/td>\nWide light source<\/td>\nPenumbra<\/td>\n<\/tr>\n
      6.<\/td>\nRegular reflection<\/td>\nGlossy surface<\/td>\n<\/tr>\n
      7.<\/td>\nThe sun<\/td>\nPrimary source of light<\/td>\n<\/tr>\n
      8.<\/td>\nBand of seven colors<\/td>\nSpectrum of light<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

      V. Answer the following questions in short:<\/span><\/p>\n

      Question 1.
      \nWith the help of a diagram, state the laws of reflection
      \nAnswer:
      \nLaws of reflection:
      \n\"Samacheer<\/p>\n

        \n
      1. The angle of incidence is always equal to the angle of reflection li =l*<\/li>\n
      2. The incident ray, the reflected ray and the normal at the point of incidence lie on the same plane.<\/li>\n<\/ol>\n

        Question 2.
        \nFigure shows a pencil placed above a mirror<\/p>\n

        \"Samacheer
        \na) Draw its image formed by the mirror
        \nb) Show how light rays from the object are reflected at the mirror to form the image for the eye.
        \nAnswer:<\/p>\n

        \"Samacheer<\/p>\n

        Question 3.
        \nA person is looking at the image of a tree in a mirror placed 3.5 m in front of him. Given that the tree is at 0.5 m behind his eyes. Find the distance between the image of the tree and his eyes. What are needed to see an object?
        \nAnswer:
        \n\"Samacheer
        \nDistance between the person and the mirror = 3.5 m
        \nDistance between the person and tree (object) = 0.5 m
        \nThe image formed in the mirror = 4 m
        \nThe distance between the image of the tree and his eyes = 4 + 3.5 = 7.5<\/p>\n

        Question 4.
        \nWhat are luminous objects?
        \nAnswer:
        \nAll objects which emit light energy by themselves are called luminous objects. Ex.: Sun, electric bulb.<\/p>\n

        \"SamacheerKalvi.Guru\"<\/p>\n

        Question 5.
        \nIs thr moon a luminous object?
        \nAnswer:
        \nNo, the moon is non-luminous. The reason is that moon does not produce its own light. Instead, it reflects the light of the sun falling on it.<\/p>\n

        Question 6.
        \nWhat are the three types of materials based on the absorption of light?
        \nAnswer:<\/p>\n

          \n
        1. Transparent Material<\/li>\n
        2. Translucent Material<\/li>\n
        3. Opaque Material<\/li>\n<\/ol>\n

          Question 7.
          \nWhat are the parts of shadow?
          \nAnswer:<\/p>\n

            \n
          1. Umbra<\/li>\n
          2. Penumbra<\/li>\n<\/ol>\n

            Question 8.
            \nWhat are the properties of shadow?
            \nAnswer:
            \nProperties of shadow:<\/p>\n

              \n
            1. All objects do not form shadows. Only opaque objects form shadows.<\/li>\n
            2. Shadows will be formed in the opposite side of light source.<\/li>\n
            3. It cannot be determined the characteristics of an object by its shadow.<\/li>\n
            4. The shadow will be always darker, whatever may be the color of light rays.<\/li>\n
            5. Light source, opaque object are shadow all are in a straight line.<\/li>\n
            6. The size of shadow depends upon the distance between light source and object and the distance between object and the screen.<\/li>\n<\/ol>\n

              Question 9.
              \nWhat is plane mirror?
              \nAnswer:
              \nA plane mirror is a mirror with a flat reflective surface. A plane mirror makes an image of objects in front of it.<\/p>\n

              Question 10.
              \nWhat is prism?
              \nAnswer:
              \nA prism is an object made up of a transparent material, like glass or plastic that has at least two flat surfaces that form an acute angle (less than 90\u00b0).<\/p>\n

              Question 11.
              \nWhat do you mean by visible light?
              \nAnswer:
              \nVisible light is a spectrum of a number of waves with different wavelength range from 400nm to 700nm (lnm = 10″9 meter) each wave has a definite wavelength represents a particular colour.<\/p>\n

              \"SamacheerKalvi.Guru\"<\/p>\n

              Question 12.
              \nWrite the items given here in the correct column (Stars, brick walls, plants, mirror, planets, electric light bulb, candle)<\/p>\n\n\n\n\n
              Sources of Light<\/td>\nObjects that reflect light<\/td>\n<\/tr>\n
              <\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

              Answer:<\/p>\n\n\n\n\n\n\n\n
              Sources of Light<\/td>\nObjects that reflect light<\/td>\n<\/tr>\n
              Stars<\/td>\nBrick walls<\/td>\n<\/tr>\n
              Electric light bulb<\/td>\nPlants<\/td>\n<\/tr>\n
              Candle<\/td>\nMirror<\/td>\n<\/tr>\n
              <\/td>\nPlanets<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

              Question 13.
              \nA boy of height lm 45 cm is standing in front of a long mirror at a distance of 2 m. From this information, fill up the following sentences:
              \na) The distance between the boy and his image is ______
              \nb) The height of the image is ______
              \nc) When the boy moves 1 m forward, the distance between her and her image is ______
              \nAnswer:
              \n(a) The distance between the boy and his image is 4m
              \n(b) The height of the image is same.
              \n(c) When the boy moves 1 m forward, the distance between her and her image is 2m.<\/p>\n

              Question 14.
              \nDraw a diagram of a pinhole camera showing the rays of light passing between the Object and its image
              \nAnswer:<\/p>\n

              \"Samacheer<\/p>\n

              Question 15.
              \nWhy is the writing on the front of an ambulance back to front as shown in the picture
              \n\"Samacheer
              \nAnswer:<\/p>\n

                \n
              1. This is due to lateral inversion.<\/li>\n
              2. The phenomenon due to which the left side of an object appears to be right side of the object in its image in a reflecting medium (mirror).<\/li>\n
              3. So that drivers see the word the right way around in their rear-view mirror.<\/li>\n<\/ol>\n

                Question 16.
                \nExplain with examples, why some capital letters look the same in a mirror but others are reversed.
                \nAnswer:
                \nAny letter that has a bilateral symmetry will have its mirror image the same as that of the object.
                \nExample:
                \n\"Samacheer<\/p>\n

                \"SamacheerKalvi.Guru\"<\/p>\n

                Question 17.
                \nTwo plane mirrors M1 and M2 are placed perpendicular with each other, as shown in figure. The ray AB makes an angle 39\u00b0 with the plane mirror M , then<\/p>\n

                  \n
                1. The reflected rays are _________, ____________<\/li>\n
                2. The incident rays are _________, ____________<\/li>\n
                3. What is the angle of incident corresponding to the ray BC?<\/li>\n
                4. What is the angle of reflection corresponding to the ray CD<\/li>\n<\/ol>\n

                  \"Samacheer
                  \nAnswer:<\/p>\n

                  \"Samacheer<\/p>\n

                    \n
                  1. BC, CD<\/li>\n
                  2. AB, BC<\/li>\n
                  3. \\(\\lfloor i\\) = 39\u00b0<\/li>\n
                  4. \\(\\lfloor r\\) = 39\u00b0<\/li>\n<\/ol>\n

                    Question 18.
                    \nRaj an was playing with the mirror images of a clock. He looked at the clock in his roomIt was showing 1:40. Draw the position of the hands on the real clock and on its mirror reflection .Write below the picture what time each picture<\/p>\n

                    \"Samacheer
                    \nAnswer:<\/p>\n

                    \"Samacheer<\/p>\n

                    Question 19.
                    \nWhat is reflection of light?
                    \nAnswer:
                    \nThe bouncing back of light from a reflecting surface of an object is called as reflection of light<\/p>\n

                    Question 20.
                    \nIf a ray of light is falling on a plane mirror at an angle of 50\u00b0 is formed, what will be the angle of reflection?
                    \nAnswer:<\/p>\n

                    \"Samacheer
                    \nAngle of incidence \\(\\lfloor i\\) = 90\u00b0 – 50\u00b0
                    \n\\(\\lfloor i\\) = 40\u00b0
                    \nAccording to laws of reflection,
                    \n\\(\\lfloor i\\) = \\(\\lfloor k\\)
                    \nAngle of incidence = Angle of reflection
                    \n\\(\\lfloor i\\) = 40\u00b0
                    \n\u2234 \\(\\lfloor r\\) – 40\u00b0
                    \nAngle of reflection \\(\\lfloor r\\) = 40\u00b0<\/p>\n

                    Question 21.
                    \nWhat do you mean by lateral inversion?
                    \nAnswer:
                    \nThe phenomenon due to which left hand side of object appears as right hand side and vice versa is called lateral inversion.<\/p>\n

                    \"SamacheerKalvi.Guru\"<\/p>\n

                    Question 22.
                    \nHow do you obtain a spectrum of light?
                    \nAnswer:
                    \nWhen white light is made to fall on the surface of a prism, it disperses and we obtain a spectrum of light.<\/p>\n

                    Question 23.
                    \nWhy do we see white color in Newton\u2019s disc, when we rotate it very fast?
                    \nAnswer:
                    \nWhen the disc turned quickly, the retina receives the sensation of the spectrum simultaneously and disc appears white.<\/p>\n

                    Question 24
                    \nWhat is a shadow? What things are necessary for the formation of a shadow?
                    \nAnswer:<\/p>\n

                      \n
                    1. Shadows are formed because light travels in straight lines.<\/li>\n
                    2. Shadow is always against, opposite side of light source.<\/li>\n
                    3. Shadow is formed by opaque objects that stop high from propagating.<\/li>\n
                    4. Things necessary for the formation of shadow: source of light,opaque object<\/li>\n<\/ol>\n

                      VI. Answer the following questions in detail:<\/span><\/p>\n

                      Question 1.
                      \nWhat are regular and irregular reflection? Explain with the help of diagrams
                      \nAnswer:
                      \n(i) Regular reflection When a parallel beam of light on striking some smooth and polished surface is reflected as a parallel beam of light, such a reflection is called regular reflection.<\/p>\n

                      \"Samacheer
                      \n(ii) Irregular reflection : When a parallel beam of light, on striking some rough surface, is reflected in different directions, then such a reflection is called irregular or diffused reflection.<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 2.
                      \nWhat are the difference between luminous and non-luminous objects? Give two examples of each.
                      \nAnswer:<\/p>\n\n\n\n\n\n
                      <\/td>\nLuminous objects<\/td>\nNon-luminous objects<\/td>\n<\/tr>\n
                      1.<\/p>\n

                       <\/td>\n

                      		All objects which emit light energy by themselves are called luminous objects.<\/td>\nAll objects which do not emit light energy of their own, but reflect the light energy falling on them and hence, become visible are called non- luminous object.<\/td>\n<\/tr>\n
                      2.<\/td>\nEx.: Sun, stars, torch light, burning candle etc.<\/td>\nEx.: Metals, trees, houses, stones, moon etc.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                      Question 3.
                      \nWrite about two everyday situations that tell you that light travels in a straight line.
                      \nAnswer:<\/p>\n

                        \n
                      1. Formation of shadow: Shadows are formed when some light rays continue its travel in straight lines while other rays are stopped by an object.<\/li>\n
                      2. When there is a small hole in a room, light travels only in a straight line.<\/li>\n<\/ol>\n

                        \"SamacheerKalvi.Guru\"<\/p>\n

                        Question 4.
                        \nDifferentiate between a reflection and a shadow
                        \nAnswer:<\/p>\n\n\n\n\n\n
                        Reflection<\/td>\nShadow<\/td>\n<\/tr>\n
                        When light falls on a surface, the direction of ray is changed. This change in direction is known as reflection of light.<\/td>\nShadow is an image formed by obstruction of light.<\/td>\n<\/tr>\n
                        Eg.: You see your reflection in a pool of water or mirror.<\/td>\nEg.: If you place your hand in front of a candle, you will see the image of the hand on the wall. This image will show only the outline of the object placed in front of the light source.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                        Question 5.
                        \nWhat are the characteristics of an image formed in a plane mirror?
                        \nAnswer:<\/p>\n

                          \n
                        1. Image formed in a plane mirror is upright.<\/li>\n
                        2. Image formed in a plane mirror is virtual The image is of the same size as the object<\/li>\n
                        3. The distance of the image from the plane mirror is equal to the distance of the object from the mirror.<\/li>\n
                        4. Image is laterally inverted.<\/li>\n<\/ol>\n

                          Question 6.
                          \nDescribe the picture<\/p>\n

                          \"Samacheer
                          \nAnswer:<\/p>\n

                            \n
                          1. When the tube is bent, we cannot see the source of light<\/li>\n
                          2. When the tube is held straight we can see the flame. The two pictures verify that light travels in straight lines. This is known as rectilinear propagation of light.<\/li>\n<\/ol>\n

                            Question 7.
                            \nDefine the following terms
                            \na. Incident ray
                            \nb. Reflected ray
                            \nc. Normal
                            \nd. Angle of incidence
                            \nAnswer:
                            \n(a) Incident tavi The ray of light that falls on the surface of the reflection materials.
                            \n(b) Reflected ray: The ray of light that comes from the point when the incident ray falls on the reflection material.
                            \n(c) Normal: The perpendicular line drawn from, the point of incidence to the plane of reflecting surface is called normal.
                            \n(d) Angl e of incidence The angle formed between the incident ray PO and the normal \u2018ON\u2019 is angle of incidence.<\/p>\n

                            \"SamacheerKalvi.Guru\"<\/p>\n

                            Question 8.
                            \nCompare the images formed by plane mirror with that by pinhole camera
                            \nAnswer:
                            \nDifference between the images formed in Pinhole camera and Plane mirror:<\/p>\n\n\n\n\n\n\n
                            Image formed by Pin hole camera<\/td>\nImages formed in Plane mirror<\/td>\n<\/tr>\n
                            The image is real.<\/td>\nThe image is virtual<\/td>\n<\/tr>\n
                            The image may not be equal to the size of the object<\/td>\nThe image is equal to the size of the object<\/td>\n<\/tr>\n
                            The image is inverted<\/td>\nThe image is erect<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                            Samacheer Kalvi 7th Science Light Intext Activities<\/h3>\n

                            Activity – 4<\/span><\/p>\n

                            Let\u2019s categorize transparent material, translucent material and opaque material among f the given materials
                            \n(Clear plastic ruler, cellophane paper, some water in a glass jar, tissue paper, drinking glass, beaker, tap water, kerosene, coconut oil, note paper, card board, milk, diluted milk, aluminum foil, thick colored plastic lid, rough glass piece, measuring glass with water, wooden piece) Place all the materials given above in the dark room. Focus a torch light on one side of each material. Inspect the light coming out at the other side of each material and then classify the materials in the table.<\/p>\n\n\n\n\n\n\n\n\n\n
                            S.No<\/td>\nTransparent Material<\/td>\nTranslucent Material<\/td>\nOpaque Material<\/td>\n<\/tr>\n
                            1.<\/td>\nClear plastic ruler<\/td>\nKerosene<\/td>\nCard board<\/td>\n<\/tr>\n
                            2.<\/td>\nDrinking glass<\/td>\nMilk<\/td>\nWooden piece<\/td>\n<\/tr>\n
                            3.<\/td>\nBeaker<\/td>\ndiluted milk<\/td>\naluminium foil<\/td>\n<\/tr>\n
                            4.<\/td>\nTap water<\/td>\nrough glass piece<\/td>\nthick coloured plastic lid.<\/td>\n<\/tr>\n
                            5.<\/td>\nMeasuring glass with water<\/td>\ntissue paper<\/td>\n<\/td>\n<\/tr>\n
                            6.<\/td>\nCell phone paper<\/td>\nNote paper<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                            Activity – 6<\/span><\/p>\n\n\n\n\n\n\n\n
                            Surfaces<\/td>\nProperty of Image (Clearer \/ blurred)<\/td>\n<\/tr>\n
                            Glass<\/td>\nBlurred<\/td>\n<\/tr>\n
                            Metal Sheet<\/td>\nBlurred<\/td>\n<\/tr>\n
                            Aluminum foil<\/td>\nClearer<\/td>\n<\/tr>\n
                            Whitepaper<\/td>\nClearer<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                            Activity – 7<\/span><\/p>\n

                            There are eight letters in the word EINSTEIN
                            \n\"Samacheer<\/p>\n

                              \n
                            1. Write the word in front of a plane mirror shown in diagram<\/li>\n
                            2. Write down how these letters appear in the mirror<\/li>\n
                            3. How many of these letters appear to be different, when the word is reflected?<\/li>\n
                            4. Write down the letters that appear to be the same.<\/li>\n<\/ol>\n

                              Answer:
                              \n(i)\"Samacheer<\/p>\n

                              \"SamacheerKalvi.Guru\"<\/p>\n

                              (ii)\"Samacheer<\/p>\n

                              (iii) 3 letters (E,N,S)
                              \n(iv) I,T<\/p>\n

                              Activity – 10<\/span>
                              \nYou need Gelatin papers of Red, Blue and Yellow. Fold each gelatin paper three times and look different colour objects listed below through each folded paper. Observe what colour each object has. Write your observations in the table.<\/p>\n\n\n\n\n\n\n\n\n\n\n
                              Object<\/td>\nOriginal colour of object<\/td>\nColour through Red gelatin paper<\/td>\nColour through Blue gelatin paper<\/td>\nColour through Yellow gelatin paper<\/td>\n<\/tr>\n
                              Blue sky<\/td>\nBlue<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                              Orange flower<\/td>\nOrange<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                              Yellow banana<\/td>\nYellow<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                              leaves<\/td>\nGreen<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                              Brown trouser<\/td>\nBrown<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                              White shirt<\/td>\nWhite<\/td>\nRed<\/td>\nBlue<\/td>\nYellow<\/td>\n<\/tr>\n
                              Black board<\/td>\nBlack<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                              Samacheer Kalvi 7th Science Light Additional Questions<\/h3>\n

                              I. Choose the correct answer.<\/span><\/p>\n

                              Question 1.
                              \nWhich of the following is a natural source of light?
                              \n(a) Electric lamp
                              \n(b) Electric filament
                              \n(c) Torch light
                              \n(d) Sunlight
                              \nAnswer:
                              \n(d) Sunlight<\/p>\n

                              \"SamacheerKalvi.Guru\"<\/p>\n

                              Question 2.
                              \nLight shows ________
                              \n(a) curvilinear propagation
                              \n(b) random propagation
                              \n(c) rectilinear propagation
                              \n(d) none of these
                              \nAnswer
                              \n(c) rectilinear propagation<\/p>\n

                              Question 3.
                              \nRectilinear propagation is ________
                              \n(a) mode of travelling in straight lines
                              \n(b) mode of travelling in curved lines
                              \n(c) ability to bend around obstacles
                              \n(d) displaying the phenomenon of diffraction
                              \nAnswer
                              \n(a) made of travelling in straight lines<\/p>\n

                              Question 4.
                              \nPlane mirrors are arranged parallel to each other to get ________
                              \n(a) a single image
                              \n(b) two images
                              \n(c) a large number of reflected image
                              \n(d) no image
                              \nAnswer:
                              \n(d) two images<\/p>\n

                              Question 5.
                              \nWhich of the following is not luminous object?
                              \n(a) Sun
                              \n(b) Moon
                              \n(c) Candle
                              \n(d) Bulb
                              \nAnswer
                              \n(b) Moon<\/p>\n

                              \"SamacheerKalvi.Guru\"<\/p>\n

                              Question 6.
                              \nWhite light is composed of ________
                              \n(a) seven colours
                              \n(b) five colours
                              \n(c) three colours
                              \n(d) only one colours
                              \nAnswer:
                              \n(a) seven colours<\/p>\n

                              Question 7.
                              \nThe image which can be obtained on screen is called ________
                              \n(a) erect
                              \n(b) real
                              \n(c) virtual
                              \n(d) inverted
                              \nAnswer:
                              \n(b) real<\/p>\n

                              Question 8.
                              \nIf we mix lights of the colours of the rainbow we will get .
                              \n(a) pink light
                              \n(b) brown light
                              \n(c) colourless light
                              \n(d) black light
                              \nAnswer:
                              \n(c) colourless light<\/p>\n

                              Question 9.
                              \nWhich one of the following is involved for the formation of rainbow in the sky?
                              \n(a) Expansion of light
                              \n(b) Expansion of heat by the Sun
                              \n(c) Distance between the Earth and the Moon
                              \n(d) Dispersion of light
                              \nAnswer:
                              \n(d) Dispersion of light<\/p>\n

                              Question 10.
                              \nA virtual image is
                              \n(a) always real
                              \n(b) always uncapturable on a screen
                              \n(c) always inverted
                              \n(d) always caught on a screen
                              \nAnswer:
                              \n(b) always uncapturable on a screen<\/p>\n

                              II. Fill in the Blanks.<\/span><\/p>\n

                                \n
                              1. Objects which are able to emit light are known as ______<\/li>\n
                              2. Passing electricity through certain gases at a very low pressure can produce ______<\/li>\n
                              3. ______ is a simple device which helps us to understand about the rectilinear propagation of light.<\/li>\n
                              4. The light falling on the mirror is called ______ as and the light reflected is called<\/li>\n
                              5. The angle formed between the reflected ray and the normal is ______<\/li>\n
                              6. Light travels ______ km per second in air or vacuum.<\/li>\n
                              7. Materials that allow light to pass through completely are known as ______ material.<\/li>\n
                              8. Materials that allow light to pass through partially are called ______ materials.<\/li>\n
                              9. Materials that are not able to allow light to pass through it are called ______ materials.<\/li>\n
                              10. ______ is always against, opposite side of light source.<\/li>\n
                              11. The ______ is the darkest part of a shadow.<\/li>\n
                              12. The lighter shade of shadow is the ______<\/li>\n
                              13. Only ______ objects forms shadows.<\/li>\n
                              14. ______ eclipse occurs, when the moon arrives between the sun and the Earth.<\/li>\n
                              15. ______ cables are able to carry more signals than traditional copper cable telephone lines.<\/li>\n
                              16. The images that are obtained on a screen are called ______ and that which cannot be obtained on a screen is ______<\/li>\n
                              17. When all colours of visible light strikes the retina of our eye at the same time, our brain perceives ______<\/li>\n
                              18. ______ colour is scattered the least by air molecules.<\/li>\n
                              19. ______ is the method of creating colour by mixing various proportion of two or three distinct colours of light.<\/li>\n
                              20. ______ Magenta, Cyan and yellow are called colours.<\/li>\n<\/ol>\n

                                Answer:<\/p>\n

                                  \n
                                1. light sources<\/li>\n
                                2. Light<\/li>\n
                                3. Pin-hole camera<\/li>\n
                                4. incident ray, reflected ray<\/li>\n
                                5. angle of reflection<\/li>\n
                                6. 3 lakh<\/li>\n
                                7. transparent<\/li>\n
                                8. translucent<\/li>\n
                                9. opaque<\/li>\n
                                10. Shadow<\/li>\n
                                11. umbra<\/li>\n
                                12. penumbra<\/li>\n
                                13. opaque<\/li>\n
                                14. Solar<\/li>\n
                                15. Fibre optic<\/li>\n
                                16. real image, virtual image<\/li>\n
                                17. white<\/li>\n
                                18. Red<\/li>\n
                                19. Synthesis<\/li>\n
                                20. secondary<\/li>\n<\/ol>\n

                                  III. True or False – If false give the correct statement.<\/span><\/p>\n

                                  Question 1.
                                  \nAngle of incidence is greater than the angle of reflection.
                                  \nAnswer:
                                  \nFalse
                                  \nCorrect statement: Angle of incidence is o the angle of reflection.<\/p>\n

                                  \"SamacheerKalvi.Guru\"<\/p>\n

                                  Question 2.
                                  \nThe image formed by a plane mirror is real.
                                  \nAnswer:
                                  \nFalse.
                                  \nCorrect statement: The image formed by a plane mirror is virt ual and erect.<\/p>\n

                                  Question 3.
                                  \nDiffused reflection gives a sharp image.
                                  \nAnswer:
                                  \nFalse.
                                  \nCorrect statement: reflection gives a sharp image.<\/p>\n

                                  Question 4.
                                  \nThe image formed by a plane mirror is always that far behind the mirror as far the object lies in front of it.
                                  \nTrue.
                                  \nYou can see a rainbow only when your back is towards the sun.
                                  \nTrue.<\/p>\n

                                  Question 5.
                                  \nYou can see a rainbow only when your back is towards the sun.
                                  \nAnswer:
                                  \nTrue.<\/p>\n

                                  \"SamacheerKalvi.Guru\"<\/p>\n

                                  Question 6.
                                  \nThe image of symmetrical letters like A, H, I, M, R, K, T, U are not affected by lateral inversion.
                                  \nAnswer:
                                  \nCorrect statement: The image of symmetrical letters like A, H, I, M, T, U are not affected by lateral inversion.<\/p>\n

                                  Question 7.
                                  \nPlane mirrors are used as looking glass, to reflect light on objects and in periscopes.
                                  \nAnswer:
                                  \nTrue<\/p>\n

                                  Question 8.
                                  \nWe can not get white light when we mix seven colours.
                                  \nFalse
                                  \nCorrect statement: We can get white light when we mix seven colours.<\/p>\n

                                  Question 9.
                                  \nMaterials that allow light to pass through completely are known as transparent material
                                  \nAnswer:
                                  \nTrue<\/p>\n

                                  Question 10.
                                  \nSolar and lunar eclipses are occuring due to the property of light known as the rectilinear propagation of light.
                                  \nAnswer:
                                  \nTrue<\/p>\n

                                  IV. Match the following :<\/span><\/p>\n

                                  Question 1.<\/p>\n\n\n\n\n\n\n
                                  1.<\/td>\nRubber<\/td>\n(a)<\/td>\nErect<\/td>\n<\/tr>\n
                                  2.<\/td>\nGreased paper<\/td>\n(b)<\/td>\nInverted<\/td>\n<\/tr>\n
                                  3,<\/td>\nReal image<\/td>\n(c)<\/td>\nOpaque medium<\/td>\n<\/tr>\n
                                  4.<\/td>\nVirtual image<\/td>\n(d)<\/td>\nTranslucent medium<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                                  Answer:<\/p>\n

                                    \n
                                  1. c<\/li>\n
                                  2. d<\/li>\n
                                  3. b<\/li>\n
                                  4. a<\/li>\n<\/ol>\n

                                    Question 2.<\/p>\n\n\n\n\n\n\n
                                    1.<\/td>\nReal image<\/td>\n(a)<\/td>\nDiffuse reflection<\/td>\n<\/tr>\n
                                    2.<\/td>\nVirtual image<\/td>\n(b)<\/td>\nAn optical device which produces reflection<\/td>\n<\/tr>\n
                                    3.<\/td>\nMirror<\/td>\n(c)<\/td>\nCannot be taken on screen<\/td>\n<\/tr>\n
                                    4.<\/td>\nA type of light scattering<\/td>\n(d)<\/td>\nCan be taken on screen<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                                    Answer:<\/p>\n

                                      \n
                                    1. d<\/li>\n
                                    2. c<\/li>\n
                                    3. b<\/li>\n
                                    4. a<\/li>\n<\/ol>\n

                                      V. Assertion and Reason.<\/span><\/p>\n

                                      Mark the correct choice as
                                      \n(a) Both A and R are true and R is the correct explanation of assertion.
                                      \n(b) Both A and R are true but R is not the correct explanation of assertion.
                                      \n(c) A is true but R is false.
                                      \n(d) A is false but R is true.<\/p>\n

                                      \"SamacheerKalvi.Guru\"<\/p>\n

                                      Question 1.
                                      \nAssertion (A) : A plane mirror produces virtual, erect image for any position of the object.
                                      \nReason (R) : Lateral inversion is an important property of image formed by a plane mirror.
                                      \nAnswer:
                                      \n(b) Both A and R are true but R is not the correct explanation of assertion.
                                      \nCorrect reason: It is because of the property of image formed in a plane mirror.<\/p>\n

                                      Question 2.
                                      \nAssertion (A) : When an object is placed between two plane mirrors; then all the images
                                      \nfound are of unequal intensity.
                                      \nReason (R) : In case of plane parallel mirrors, only two images are possible.
                                      \nAnswer:
                                      \n(c) A is true but R is false
                                      \nCorrect reason: In case of plane parallel mirrors, infinite images are formed.<\/p>\n

                                      Question 3.
                                      \nAssertion (A) : Virtual object can\u2019t be seen by human eye.
                                      \nReason (R) : Virtual image is formed by converging rays.
                                      \nAnswer:
                                      \n(c) A is true but R is false
                                      \nCorrect reason: Virtual image is formed by diverging rays.<\/p>\n

                                      Question 4.
                                      \nAssertion (A) : A ray incident along normal to the mirror retraces its path.
                                      \nReason (R) : In reflection, angle of incidence is always equal to angle of reflection.
                                      \nAnswer:
                                      \n(a) Both A and R are true and R is the correct explanation of assertion<\/p>\n

                                      VI. Very short Answers:<\/span><\/p>\n

                                      Question 1.
                                      \nWhat is the composition of sunlight?
                                      \nAnswer:
                                      \nSunlight is a mixture of seven colours.<\/p>\n

                                      Question 2.
                                      \nHow does light travel?
                                      \nAnswer:
                                      \nLight travels along a straight line.<\/p>\n

                                      \"SamacheerKalvi.Guru\"<\/p>\n

                                      Question 3.
                                      \nWhat kind of surface reflects light?
                                      \nAnswer:
                                      \nSmooth and shiny surface reflects light.<\/p>\n

                                      Question 4.
                                      \nName the triangular piece of glass that splits white light into different colours.
                                      \nAnswer:
                                      \nPrism.<\/p>\n

                                      Question 5.
                                      \nWhat is reflection of light?
                                      \nAnswer:
                                      \nWhen light falls on smooth surface like mirror then it changes its direction, it is called reflection.<\/p>\n

                                      Question 6.
                                      \nState the size of the image formed by a plane mirror?
                                      \nAnswer:
                                      \nThe size of image formed by a plane mirror is same as that of the object infront of the mirror.<\/p>\n

                                      Question 7.
                                      \nWhat is Newton\u2019s disc?
                                      \nAnswer:
                                      \nNewton Disc is a card board disc with seven equal sectors colored red, yellow, orange, green, blue, indigo and violet. When the disc turned quickly, the retina receives the sensation of the spectrum simultaneously and disc appears white.<\/p>\n

                                      Question 8.
                                      \nWhat is an eclipse?
                                      \nAnswer:
                                      \nAn eclipse is an incident, when any astronomical object is partially or fully obscured due to the placement of another astronomical object in the presence of light.<\/p>\n

                                      Question 9.
                                      \nWhat is light?
                                      \nAnswer:
                                      \nLight is type of energy, that helps us to see all the things around us.<\/p>\n

                                      VII. Short Answer.<\/span><\/p>\n

                                      Question 1.
                                      \nWhat is natural sources of light? Give example.
                                      \nAnswer:
                                      \nSources which emit light naturally are known as natural sources of light. The Sun is the primary and the major source of natural light.<\/p>\n

                                      \"SamacheerKalvi.Guru\"<\/p>\n

                                      Question 2.
                                      \nMention the properties of light.
                                      \nAnswer:
                                      \nLight has some fundamental properties as mentioned below.<\/p>\n

                                        \n
                                      • Rectilinear propagation of light<\/li>\n
                                      • Reflection<\/li>\n
                                      • Speed<\/li>\n
                                      • Interaction of light with matter.<\/li>\n<\/ul>\n
                                          \n
                                        1. Types of material according to permeability.<\/li>\n
                                        2. Formation of shadows.<\/li>\n
                                        3. Plane mirror and images.<\/li>\n
                                        4. Spectrum.<\/li>\n<\/ol>\n

                                          Question 3.
                                          \nState laws of reflection.
                                          \nAnswer:
                                          \nLaws of reflection:<\/p>\n

                                            \n
                                          1. The angle of incidence is always equal to the angle of reflection. \\(\\lfloor i\\) = \\(\\lfloor r\\)<\/li>\n
                                          2. \u00a0The incident ray, the reflected ray and the normal at the point of incidence lie on the same plane.<\/li>\n<\/ol>\n

                                            Question 4.
                                            \nDefine transparent materials. Give example.
                                            \nAnswer:<\/p>\n

                                              \n
                                            1. Materials that allow light to pass through completely are known as transparent material.<\/li>\n
                                            2. Example: Eye glasses, clear drinking glass, clear water, face glasses used in buses.<\/li>\n<\/ol>\n

                                              Question 5.
                                              \nDefine opaque material. Give example.
                                              \nAnswer:<\/p>\n

                                                \n
                                              1. Materials that are not able to allow light to pass through, are called opaque material.<\/li>\n
                                              2. Example: Wall, thick card board, stone, etc.<\/li>\n<\/ol>\n

                                                Question 6.
                                                \nWhat is lunar eclipse?
                                                \nAnswer:<\/p>\n

                                                  \n
                                                1. Lunar eclipse occurs, when the Earth (E) comes between the Sun (S) and the Moon (M).<\/li>\n
                                                2. The Earth prevents light coming from the Sun and makes shadow on the Moon. This is lunar eclipse.<\/li>\n<\/ol>\n

                                                  Question 7.
                                                  \nWhy danger lights in vehicles are red in colour?
                                                  \nAnswer:<\/p>\n

                                                    \n
                                                  1. Red color is scattered the least by air molecules.<\/li>\n
                                                  2. Red color has the highest wavelength of all the other colors. So red color is able to travel the longest distance through air, fog.<\/li>\n<\/ol>\n

                                                    \"SamacheerKalvi.Guru\"<\/p>\n

                                                    Question 8.
                                                    \nWhat is meant by synthesis of colour?<\/p>\n

                                                      \n
                                                    1. Synthesis of colour is the method of creating colour by mixing various proportion of two (or) three distinct colours of light. .<\/li>\n
                                                    2. These distinct colours are Red, Green and Blue called as primary colours.<\/li>\n<\/ol>\n

                                                      Question 9.
                                                      \nWhen lighting a bulbs in a dark room, light spreads the whole room quickly. Give reason.
                                                      \nAnswer:<\/p>\n

                                                        \n
                                                      1. When lighting a bulb in a dark room, light spreads the whole room quickly.<\/li>\n
                                                      2. This is because the light travels very fast.<\/li>\n
                                                      3. Light travels three lakh kilometers per second in air or vacuum.<\/li>\n
                                                      4. In theory, nothing can travel faster than light.<\/li>\n<\/ol>\n

                                                        VIII. Long Answer:<\/span><\/p>\n

                                                        Question 1.
                                                        \nWrite the difference between real image and virtual image.
                                                        \nAnswer:<\/p>\n\n\n\n\n\n\n
                                                        <\/td>\nReal image<\/td>\nVirtual image<\/td>\n<\/tr>\n
                                                        1.<\/td>\nIt can be taken on a screen.<\/td>\nIt cannot be taken on a screen.<\/td>\n<\/tr>\n
                                                        2.<\/td>\nThe rays of light, after reflection<\/td>\nThe rays of light, after reflection appear to<\/td>\n<\/tr>\n
                                                        3.<\/td>\nIt is always inverted<\/td>\nIt is always erect but laterally inverted<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                                                        Question 2.
                                                        \nExplain the importance of optical fiber.
                                                        \nAnswer:<\/p>\n

                                                          \n
                                                        1. Optical fiber is a device that works on the principle of total internal reflection by which light signals (huge data) can be transmitted from one place to another place with a negligible loss of energy in a very short time.<\/li>\n
                                                        2. It consists of a cable having one or more thin flexible fibers with a glass core through which light signals can be sent.<\/li>\n
                                                        3. Optical fiber can be twisted and bent easily.<\/li>\n
                                                        4. When a light a ray of light is incident at one end of the core of optical fiber, it suffers total internal reflection at the many places inside the fiber and emerges at the other end with negligible loss of energy.<\/li>\n
                                                        5. The data or information in the form of pulses of light, can be sent through bundles of optical fibers.<\/li>\n
                                                        6. Optical fibers have become very important in high-speed communications, such as cable TV and high-speed broadband services.Fiber optic cables are able to carry more signals than traditional copper cable telephone lines.<\/li>\n<\/ol>\n

                                                          Question 3.
                                                          \nWith help of a diagram, write a note on : a. Solar eclipse, b. Lunar eclipse.
                                                          \nAnswer:
                                                          \n(a) Solar eclipse<\/p>\n

                                                          \"Samacheer
                                                          \nSolar eclipse occurs, when the Moon arrives between the Sun (S) and the Earth(E). The shadow of the Moon appears on the Earth at A as shown in picture. Hence, those who are at the region A are unable to see the Sun instantly. This is solar eclipse. But, those who are at the region B and C are able to see the sun partially.
                                                          \n(b) Lunar eclipse<\/p>\n

                                                          \"Samacheer
                                                          \nLunar eclipse: Lunar eclipse occurs, when the Earth (E) comes between the Sun (S) and the Moon (M). The Earth prevents light coming from the Sun and makes shadow on the Moon. This is lunar eclipse<\/p>\n

                                                          IX. Problems for practice:<\/span><\/p>\n

                                                          Question 1.
                                                          \nCalculate the number of images formed by plane mirrors kept at an angle of 10\u00b0 to each others.
                                                          \nSolution:
                                                          \nNumber of image n = \\(\\frac { 360\u00b0 }{ \u03b8}\\) – 1 = \\(\\frac { 360\u00b0 }{ 10\u00b0}\\) – 1
                                                          \n= 36 – 1
                                                          \n= 35 images<\/p>\n

                                                          Question 2.
                                                          \nA ray of light fall on a plane surface at an angle of incidence 9\u00b0 and reflection occurs. Calculate the angle of reflection in degree.
                                                          \nSolution:
                                                          \nBy first law of reflection, angle of incidence is always equal to angle of reflection.
                                                          \n\\(\\lfloor i\\) = \\(\\lfloor r\\) . Here, angle of incidence is 9\u00b0. So angle of reflection must be equal to 9\u00b0.<\/p>\n

                                                          \"SamacheerKalvi.Guru\"<\/p>\n

                                                          Question 3.
                                                          \nA plane mirror forms a virtual image. The distance between Maria and her image in a plane mirror is 10 m. How much distance should she move in order to get the distance of 5 m between herself and her image?
                                                          \nSolution:
                                                          \n\"Samacheer
                                                          \nThe distance between Maria and her image in a plane mirror = 10 m
                                                          \n\"Samacheer
                                                          \nSo, she shouuld move a distance of 2.5 m toward the plane mirror<\/p>\n

                                                          X. Higher order thinking skill (HOTS) :<\/span><\/p>\n

                                                          Question 1.
                                                          \nWhy are we able to see the tap water in a glass even though it is colourless?
                                                          \nAnswer:
                                                          \nTop water reflects the light into our eyes. As long as an object reflects light into our eyes, we can see it.<\/p>\n

                                                          Question 2.
                                                          \nImagine that parallel rays are incident on an irregular surface. Are the rays reflected from this surface parallel to each other?
                                                          \nAnswer:
                                                          \nNo, the reflected rays from irregular surface are in different directions.<\/p>\n

                                                          Question 3.
                                                          \nRam planned an activity to observe an object through pipes as shown in figure, so that he could see objects which he could not directly see.<\/p>\n

                                                          \"Samacheer
                                                          \n(a) Mention how many mirrors should he use to see the objects.
                                                          \n(b) If any of the mirrors is removed, will he be able to see the objects?
                                                          \n(c) Indicate the positions of the mirrors in the figure.
                                                          \nAnswer:
                                                          \n(a) Number of mirrors = 3
                                                          \n(b) He will not be able to see the objects if any of the mirror is removed, since he will not get the rays after removal of mirror.
                                                          \n\"Samacheer<\/p>\n","protected":false},"excerpt":{"rendered":"

                                                          Students can Download Science Chapter 1 Light Questions and Answers, Notes Pdf, Samacheer Kalvi 7th Science Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations. Tamilnadu Samacheer Kalvi 7th Science Solutions Term 3 Chapter 1 Light Samacheer Kalvi 7th Science Light Textual […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","footnotes":""},"categories":[5],"tags":[],"blocksy_meta":"","jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/posts\/7317"}],"collection":[{"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/comments?post=7317"}],"version-history":[{"count":1,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/posts\/7317\/revisions"}],"predecessor-version":[{"id":55398,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/posts\/7317\/revisions\/55398"}],"wp:attachment":[{"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/media?parent=7317"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/categories?post=7317"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/tags?post=7317"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}