Sources of Light

Q.

Moon is a luminous object.

1. Non-luminous

2. none of these

Q.

Which of the following is a luminous body?

1. Luminous

2. Stars

3. Moon

4. Torch

Q.

Which of the following is a non-luminous body?

1. Flame

2. Earth

3. Star

4. Sun

Q.

Question 10

Three torches A, B and C shown in Fig. are switched on one by one. The light from which of the torches will not form a shadow of the ball on the screen.

Q. is a living luminous object.

1. The Sun
2. The Moon
3. A human
4. A firefly

Q.

The flame of a gas stove is non-luminous.

1. Non-luminous

2. Luminous

Q.

Which of the following is a non-luminous object?

1. Moon

2. Sun

3. Firefly

4. Star

Q. Which of the following source of light is a natural source?

1. Bulb
2. Tubelight
3. Glow worm
4. Laser torch

Q.

When a number of rays travel together in one direction, it is called a ______ of light.

Q.

A firefly produces light through a process called_______

1. Radiation

2. Migration

3. Luminofriction

4. Bioluminescence

Q.

The source of light which is of the size of pinhead of a common pin is known as the

1. Ray of light

2. Point source of light

3. Parallel beam of light

4. Extended source of Light

Q.

Define bio-luminescence?

Q.

What is meant by a luminous object? Name two luminous objects.

Q.

The dark region formed on a screen when light falls on a opaque object is called ___.

1. opaque region

2. shadow

3. transparent region

4. eclipse

Q. In the given figure, identify the shape of the shadow formed on the screen by the bottle.

1. Shape A
2. Shape B
3. Shape C
4. Shapes A and B

Q. Objects that emit their own light are called objects.

1. luminous
2. opaque
3. transparent
4. translucent

Q. The shadow formed on the screen will be ___________ if light falls vertically on the cone (as shown in the figure).

1. circular
2. rectangular
3. conical
4. triangular

Q.

Which of the following object(s) is luminous?

1. Table

2. Moon

3. Earth

4. Sun

Q. Which of the following luminous body produce light using nuclear energy?

1. Sun
2. Glow worm
3. Bulb
4. Candle

Q.

Objects that emit their own light are called?

1. Opaque objects

2. Luminous objects

3. Transparent objects

4. Translucent objects

Q. On a bright sunny day, Shaunak observed the sun through a small hole made in a sheet of foil. The image obtained seemed to be upright. What could be the reason for this?

1. Sun is spherical in shape
2. Sun provides light to Earth
3. Sun is a star
4. Sun produces heat

Q. Even though space is dark you can see the sun because:

1. Sun is hot
2. Sun is very big
3. Sun emits light
4. All of them

Q. Which one of the following reasons would one consider as more possible for the warning lights to be on?

1. There was a shower of debris
2. Jack was yelling
3. A catastrophe was imminent
4. The moon was looming close and big

Q. Which of the following can never form a circular shadow?

1. A ball
2. A flat disc
3. A shoebox
4. An ice cream cone

Q.

Which of the following is/are examples of living things which emit light?

1. Bee

2. Butterfly

3. Jugnu (firefly)

4. Stars

Q. What did the little boy see inside the apple?

Q. Solve the following crossword puzzle:
Figure

Across
3. Bodies emitting light of their own
4. It is the dark outline of an object

Down
1. It is a natural source of light
2. It is a living source of light

Q. Define the terms: a ray of light and a beam of light. [2 marks]

Q. The _____ and _____ are the natural sources of light.

Q. Formation of shadows suggests that light travels in a
(a) vacuum
(b) straight line
(c) curved path
(d) none of these