Physics
Assertion (A) : Opaque objects cast shadows.
Reason (R) : Opaque objects do not allow light to pass through.
- Both A and R are true, and R is the correct explanation of A.
- Both A and R are true, but R is not the correct explanation of A.
- A is true, and R is false.
- A is false, and R is true.
Answer
Both A and R are true, and R is the correct explanation of A.
Reason —
Assertion (A) is true because a shadow is formed when light is blocked by an object. Since opaque objects block light completely, they produce a dark shadow on the opposite side of the light source.
Reason (R) is true because opaque objects stop all the light from passing through them due to this, no light reaches the space behind them, and a shadow is formed there.
Hence, here the reason (R) clearly explains the assertion (A).
Related Questions
Assertion (A) : Luminous objects emit light.
Reason (R) : Sun is a natural source of light and bulbs are artificial source of light.
- Both A and R are true, and R is the correct explanation of A.
- Both A and R are true, but R is not the correct explanation of A.
- A is true, and R is false.
- A is false, and R is true.
Assertion (A) : Light scatters when it is passed through air.
Reason (R) : Light maybe be absorbed, deflected, passed through or bounced back.
- Both A and R are true, and R is the correct explanation of A.
- Both A and R are true, but R is not the correct explanation of A.
- A is true, and R is false.
- A is false, and R is true.
Assertion (A) : Solar eclipse occurs when the earth, moon and sun come in a straight line.
Reason (R) : Solar eclipse occurs on a new moon day.
- Both A and R are true, and R is the correct explanation of A.
- Both A and R are true, but R is not the correct explanation of A.
- A is true, and R is false.
- A is false, and R is true.
Mona went to Rohini's house on a Sunday morning. She noticed that all the lights in Rohini's house were switched off. She switched on the lights of the house in the evening. Mona also noticed that Rohini switched off the lights and fan every time she left the room.
Now, answer the following questions.
(a) What was the source of light in Rohini's house in the daytime?
(b) What was the source of light in Rohini's house in the evening?
(c) Why do you think she turned off the fans and lights when she left the room every time?