Light: Shadows and Reflections — Hard

Q1. Consider the following statements about luminous and non-luminous objects. I. The Sun is the main source of natural light on the Earth. II. The Moon is a luminous object that emits its own light. III. A mirror is non-luminous as it only reflects light. Which statements are correct?

• A. I and II only.
• B. II and III only.
• C. I and III only.
• D. All three.

Q2. In a figure, four students — Sahil, Rekha, Patrick and Qasima — try to see a candle flame through different arms of a fixed cross-shaped pipe. Only one of them can see the flame. The student who can see it is the one whose

• A. pipe makes a 45-degree bend before the candle.
• B. pipe is closest to the candle in length.
• C. eye, the pipe arm and the candle lie in the same straight line.
• D. pipe is bent twice between the eye and the candle.

Q3. Statements about shadows made by different materials are given. I. Opaque objects form darker shadows. II. Translucent objects make lighter shadows. III. Some transparent objects can also create faint shadows. Which combination is correct?

• A. I and II only.
• B. II and III only.
• C. I and III only.
• D. All three.

Q4. Assertion (A): When the object is moved closer to the screen, keeping the torch and screen fixed, its shadow becomes smaller. Reason (R): The geometric divergence of light rays from a point source produces a larger shadow when the object is far from the screen.

• A. Both A and R are true, and R is the correct explanation of A.
• B. Both A and R are true, but R is NOT the correct explanation of A.
• C. A is true, R is false.
• D. A is false, R is true.

Q5. Statement A: The image formed by a plane mirror is laterally inverted. Statement B: The mirror images of the alphabets T and O appear identical to themselves. Choose the correct option.

• A. Both statements are true.
• B. Both statements are false.
• C. Statement A is true, but Statement B is false.
• D. Statement A is false, but Statement B is true.

Q6. In a figure, scenario (i) shows a ball close to a fixed torch and far from the wall, while scenario (ii) shows the same ball close to the wall and far from the torch. Which option correctly matches the size of the shadow on the wall?

• A. Both shadows are equal in size.
• B. Scenario (i) gives a smaller shadow; scenario (ii) gives a larger shadow.
• C. Scenario (i) gives a larger shadow; scenario (ii) gives a smaller shadow.
• D. No shadow is formed in either scenario.

Q7. When two torches are placed on the left side of the ball, with the screen on the right, which statement is correct?

• A. A bright spot appears on the screen.
• B. Two shadows of the ball appear on the screen.
• C. Only one large shadow appears.
• D. No shadow appears because two light sources cancel out.

Q8. Consider three statements about images. I. A plane mirror image is laterally inverted, not upside down. II. A pinhole camera image is upside down (vertically inverted). III. Both images can be caught on a screen. Which combination is correct?

• A. I and II only.
• B. II and III only.
• C. I and III only.
• D. All three.

Q9. About the image of a pen formed by a plane mirror (Fig. 11.10), which set of properties is correct?

• A. Same size, inverted upside down, can be obtained on a screen.
• B. Smaller size, erect, can be obtained on a screen.
• C. Same size, erect, cannot be obtained on a screen, laterally inverted.
• D. Magnified, erect, cannot be obtained on a screen.

Q10. From the list — Mars, Moon, Pole Star, Sun, Venus, mirror — which are luminous objects?

• A. Moon and mirror only.
• B. Sun and Pole Star only.
• C. Mars, Venus and the Moon.
• D. Sun, Moon and mirror.

Q11. The word 'AMBULANCE' is written in mirror-reversed letters on the front of an ambulance. The best explanation is that

• A. drivers ahead read the word through their rear-view mirror, which laterally inverts it back to 'AMBULANCE'.
• B. the ambulance must look mysterious to other drivers.
• C. the paint reflects light in a different colour.
• D. the word is shorter to read when reversed.

Q12. Assertion (A): The image formed by a pinhole camera of a tree shows the actual colours of the tree. Reason (R): A pinhole camera works by reflection of light from a curved mirror.

• A. Both A and R are true, and R is the correct explanation of A.
• B. Both A and R are true, but R is NOT the correct explanation of A.
• C. A is true, R is false.
• D. A is false, R is true.

Q13. Can a Z-shaped tube with two plane mirrors smaller than its diameter act as a periscope? The correct answer is

• A. no, because periscopes use only convex mirrors.
• B. yes, by fixing the two mirrors at the two bends so that they face each other at 45 degrees.
• C. no, because Z-shaped tubes cannot reflect light.
• D. yes, by placing both mirrors at the same bend.

Q14. Consider three statements on the shape of a shadow. I. The shape depends on the colour of the opaque object. II. The shape depends on the object's orientation to the light source. III. Tilting the object can change the shadow's shape. Which combination is correct?

• A. I and II only.
• B. II and III only.
• C. I and III only.
• D. All three.

Q15. Assertion (A): A small piece of a plane mirror can be used to form an image of a very tall object such as a large tree. Reason (R): A plane mirror always forms an image that is the same size as the object.

• A. Both A and R are true, and R is the correct explanation of A.
• B. Both A and R are true, but R is NOT the correct explanation of A.
• C. A is true, R is false.
• D. A is false, R is true.