Introduction to Light

Q.

Differentiate between natural and artificial sources of light.

Q. What do you mean by artificial sources of light?

Q.

Light is a form of energy

1. K

2. B

Q.

It is said that a real image is inverted, also it is said that an image formed by a cinema hall is a real image. Why are we not able to see images inverted In a cinema hall?

Q.

Choose the odd one out depending on whether the object is a natural or an artificial source of light.

1. Tubelight

2. Electric torch

3. Candle

4. Sun

Q.

Circle the odd one out.

Sun, Firefly, Moon, Tube light.

Q. A ………… is an artificial source of light.

Q. Which of the following cannot be used to measure length accurately?

1. Metre scale
2. Metre rod
3. Cubit
4. Metre tap

Q. Name two natural sources of light.

Q. Light rays exhibit _____________ .

1. rectilinear motion
2. periodic motion
3. circular motion
4. random motion

Q. A ………… is an artificial source of light.

Q.

Objects that do not allow light to pass through them are called

1. transparent objects.

2. translucent objects

3. opaque objects.

4. luminous objects.

Q. Light wave is a form of:

1. Mass
2. Force
3. Energy
4. Work

Q. Name two natural sources of light.

Q. The travelling of light can be observed with a timescale of which is part of a second.

1. microseconds
2. one-millionth
3. nanoseconds
4. one-billionth

Q.

The light emitted by a dim bulb is less intense than that emitted by a bright bulb.

1. True

2. False

Q. Objects that can emit light on their own are called ______ objects.

1. luminous
2. opaque
3. transparent
4. non-luminous

Q. Which of the following is an example of a natural source of light?
(a) Candle light
(b) An electric bulb
(c) A computer screen
(d) A firefly

Q. Name two natural sources of light and two human-made sources of light.

Q. Which of the following acts as a natural pinhole camera?

1. None of the above.
2. Gaps between the leaves
3. Water droplets
4. Branches of a tree

Q.

For what purpose can devices like the phototransistors and the photoelectric cell be used?

Q. Which of the following objects emit light on their own?

1. Sun
2. Fireflies
3. Moon
4. Earth
5. Burning candle
6. Flashlight
7. Blackboard
8. Jellyfish

Q.

Using a pinhole camera, the image of the following tree is captured.

How will the image look?

1. 

2. 

3. 
   

4. 
   

Q. Light rays exhibit _____________ .

1. rectilinear motion
2. periodic motion
3. circular motion
4. random motion

Q.

Correct the following statements:

1. The colour of the shadow of an object depends on its colour.
2. Transparent objects allow light to pass through them partially.

Q.

Which among the following requires a medium for propagation?

1. Microwaves

2. X rays

3. Sound

4. Light

Q. Light is a form of energy that travels in a straight line.

1. True
2. False

Q. Write down five man-made sources of light.

Q.

_________ are artificial source of light.

Q. 1. Example of use of candela in practical life.