Physics
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?
Answer
(a) The Sunlight (natural light) entering through windows and doors was the source of light in the daytime.
(b) The electric bulbs or tube lights (artificial light) were the source of light in the evening.
(c) She turned off the fans and lights when she left the room every time to save electricity and avoid wastage of energy, as using lights and fans unnecessarily increases power consumption.
Related Questions
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.
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.
Moon is a non-luminous body. Why do you think it shines?
Do you see shadows at night? How and why?