1. Complete Activity 11.1 (Page 124). Take a torch. Cover its glass with a chart paper which has three narrow slits as shown in Fig. 11.5. Spread a sheet of chart paper on a smooth wooden board. Fix a plane mirror strip vertically on the chart paper (Fig. 11.5). Now direct the beam of light on the mirror from the torch with slits. Place the torch in such a way that its light is seen along the chart paper on the board. Now adjust its position so that the light from the torch strikes the plane mirror at an angle (Fig. 11.5). Does the mirror change the direction of light that falls on it? Now move the torch slightly to either side. Do you find any change in the direction of reflected light?
Answer:
The activity can be carried out as follows:
Aim: To observe if and how the plane mirror changes the direction of light.
Materials Required: Torch, chart paper, wooden board, plane mirror strip.
Procedure:
(i) Cover the glass of the torch with a chart paper with three slits. Place the covered torch and the plane mirror strip on a wooden board covered with chart paper. In the image we have included the setup is done a bit differently.
(ii) Now direct the beams of light on the mirror from the torch with slits. Adjust the position of the torch so that the beams strike the plane mirror at an angle. Observe what happens.
(iii) Now move the torch slightly to either side. Observe what happens in each case.
Observations:
- The mirror will change direction of the beams of light when they fall on it.
- When you move the torch to either side the direction of the reflected light rays will also change.
- When you look into the mirror with your line of sight along the direction of the reflected light, you will see the image of the slits.
Conclusions: We conclude that:
- The plane mirror reflects light in a different direction that the direction of the incoming light rays.
- The direction of reflected light changes if the direction of incoming light changes.
“Take a torch. Cover its glass with a chart paper which has three narrow slits as shown in Fig. 11.5. Spread a sheet of chart paper on a smooth wooden board. Fix a plane mirror strip vertically on the chart paper (Fig. 11.5). Now direct the beam of light on the mirror from the torch with slits. Place the torch in such a way that its light is seen along the chart paper on the board. Now adjust its position so that the light from the torch strikes the plane mirror at an angle (Fig. 11.5). Does the mirror change the direction of light that falls on it? Now move the torch slightly to either side. Do you find any change in the direction of reflected light?” – Solved.
Related Links:
Solution to Extended Learning Problem 1
Solution to Extended Learning Problem 2
Solution to Extended Learning Problem 3
Solution to Extended Learning Problem 4
Solution to Extended Learning Problem 5
Solution to Extended Learning Problem 6
Solution to Activity 11.1
Solution to Activity 11.2
Solution to Activity 11.3
Solution to Activity 11.4
Solution to Activity 11.5
Solution to Activity 11.6
Solution to Activity 11.7
Solution to Activity 11.8
Solution to Activity 11.9
Solution to Activity 11.10
Solution to Activity 11.11
Solution to Activity 11.12
