At Bodhiclasses, we believe in simplifying science through structured answers and clear understanding. Whether you’re preparing for a class test or final exam, our curated solutions will help you grasp the concepts confidently. Here’s a complete set of solved questions from Chapter 11 of Class 7 NCERT Science – “Light: Shadows and Reflections”. All answers are short, precise, and accurate.
1. Which of the following are luminous objects?
Mars, Moon, Pole Star, Sun, Venus, Mirror
Answer: Pole Star, Sun (These emit their own light, so they are luminous.)
2. Match the items in Column A with those in Column B.
| Column A | Column B |
|---|---|
| Pinhole camera | Forms an inverted image |
| Opaque object | Blocks light completely |
| Transparent object | Light passes almost completely through it |
| Shadow | The dark region formed behind the object |
3. Sahil, Rekha, Patrick, and Qasima are trying to observe the candle flame through the pipe as shown in Fig. 11.16. Who can see the flame?
Answer: Sahil – He is directly aligned with the pipe, and since light travels in a straight line, only he can see the flame.
4. Look at the images shown in Fig. 11.17 and select the correct image showing the shadow formation of the boy.
Answer: Option (b) – This correctly shows the boy’s shadow in the direction opposite to the light source.
5. The shadow of a ball is formed on a wall by placing the ball in front of a fixed torch. In scenario (i), the ball is closer to the torch, while in scenario (ii), the ball is closer to the wall. Choose the most accurate representation of the shadows formed in both scenarios from the options provided (a and b).
Answer: Option (a) – The shadow is larger when the ball is closer to the torch and smaller when it’s closer to the wall.
6. Based on Fig. 11.18, match the position of the torch in Column A with the characteristics of the ball’s shadow in Column B.
| Column A | Column B |
|---|---|
| If the torch is close to the ball | The shadow would be larger |
| If the torch is far away | The shadow would be smaller |
| If the ball is removed from the set-up | A bright spot would appear on the screen |
| If two torches are present in the set-up on the left side of the ball | Two shadows would appear on the screen |
7. Suppose you view the tree shown in Fig. 11.19 through a pinhole camera. Sketch the outline of the image of the tree formed in the pinhole camera.
Answer: The image will be inverted (upside down) and smaller in size compared to the tree. (Note: You can draw an inverted outline of the tree with the top pointing downward.)
8. Write your name on a piece of paper and hold it in front of a plane mirror such that the paper is parallel to the mirror. Sketch the image. What difference do you notice? Explain the reason for the difference.
Answer: The image appears laterally inverted – the left side appears on the right in the mirror.
Reason: Plane mirrors reverse the sides of an image, which is why ‘AMBULANCE’ is written in reverse on vehicles.
9. Measure the length of your shadow at 9 AM, 12 PM, and 4 PM with the help of your friend. Write down your observations:
(i) At which of the given times is your shadow the shortest?
Answer: 12 PM
(ii) Why do you think this happens?
Answer: Because the Sun is directly overhead at noon, reducing the angle at which light hits the body, resulting in the shortest shadow.
10. On the basis of the following statements, choose the correct option.
Statement A: Image formed by a plane mirror is laterally inverted.
Statement B: Images of alphabets T and O appear identical to themselves in a plane mirror.
Answer: (i) Both statements are true
11. Suppose you are given a tube of the shape shown in the Fig. 11.20 and two plane mirrors smaller than the diameter of the tube. Can this tube be used to make a periscope? If yes, mark where you will fix the plane mirrors.
Answer: Yes. Place the two plane mirrors at 45° angles, one at the top and one at the bottom, facing each other inside the angled ends of the tube. This will reflect light from the top to your eye at the bottom.
12. We do not see the shadow on the ground of a bird flying high in the sky. However, the shadow is seen on the ground when the bird swoops near the ground. Think and explain why it is so.
Answer: When the bird is very high, the shadow is too faint and scattered due to the distance and diffused light. As it gets closer to the ground, the shadow becomes darker and more visible because it blocks more light.
