Light as a Form of Energy

Q.

What are Natural Sources Of Light? Give Examples.

Q.

Name any two natural sources of light.

Q.

What are colours and why do we see them?

Q. Why the colour of clothes change when they are dipped in water or any liquid and then taken out?

Q. The invisible energy that causes the sense of vision, is

1. heat
2. light
3. sound
4. electricity

Q. Rainbow is caused due to:

1. Diffraction of sun rays from water drops
2. Reflection of sunlight and air particles
3. Dispersion of sun light from water drops
4. Refraction of sun light from water drops

Q.

Differentiate natural and artificial sources of light.

Q. We are able to see things in the dark.

1. True
2. False

Q. Which of the following are properties of light?

1. Light is a form of energy.
2. Light travels in a straight line.
3. Light can travel through vacuum.
4. Light needs a medium to propagate.

Q. Why does an object appear blue in white light?

Q. Which of the following is not a periodic change?
(a) formation of a rainbow
(b) the Full Moon
(c) the occurrence of seasons
(d) day and night

Q. Why does this hat appears as black?

1. It absorbs all the light
2. It reflects all the light
3. It reflects black light
4. It reflects black light

Q. The invisible energy that causes the sense of vision, is

1. heat
2. electricity
3. light
4. sound

Q. Choose the correct statements:

1. We see objects, when light emitted from the objects enter our eyes.
2. We see objects, when light reflected from the objects enter our eyes.
3. Eyes cannot see an object in the absence of light.
4. Eyes emit light rays in all direction.

1. All the statements are correct.
2. Statements 1 and 2 are correct.
3. Statements 2 and 3 are correct.
4. Statements 1, 2, and 3 are correct.