Types of Objects

Q.

If we put a green leaf under a red light what colour will it appear?

Q.

A red Rose when seen in green light appears black . Give reason

Q.

The shadow formed due to a point source of light has_____.

1. only penumbra region

2. both umbra and penumbra regions

3. depends on the distance of source from the obstacle

4. only umbra region

Q.

When an object absorbs all the light rays falling on it, the object appears to be black in color.

1. Parallel to the incident rays

2. Parallel to each other

Q. Explain the appearance of the colour of an object on basics of absorption and reflection of light.

Q. Red light is allowed to fall on a blue object. It will appear:

1. Red
2. Blue
3. Black
4. None of these

Q.

Explain why a blue object appears black when viewed through a red glass sheet.

Q.

What Is the Abstract Noun for Bright

Q.

Is light opaque? Explain.

Q. What will a paper appearing black in sunlight appear in red light?

Q.

A green leaf in yellow light will appear blue.

1. True
2. False

Q.

All bodies which emit light energy by themselves, are called transparent bodies.

1. True
2. False

Q.

The moon is a luminous source of light.

1. True
2. False

Q.

Read the following statements and choose the correct option.

(A) Only a point source forms a complete umbra.

(B) An extended source of light forms both umbra and penumbra.

1. Only A is true.

2. Only B is true.

3. Both A and B are true.

4. Both A and B are false.

Q.

The part of a shadow that receives light from some part of the source is called ________.

Q.

Give one word for:

An object which does not allow light to pass through.

Q.

Study the table given below and answer the questions that follow.

Material	Allows light to pass through it	Does it form a shadow?
Wood	No	Yes
Butter paper	Partially	Yes
Bricks	No	Yes
Glass	Yes	No
Cardboard	No	Yes
Metal	No	Yes
Frosted glass	Partially	Yes

Objects are categorized as opaque, translucent, and transparent. Which one of these categories do not form a shadow when placed in the path of a source of light?

Q.

Encircle the odd one out. Give reasons for your choice: Fluorescent tube, the star, the moon, fire and the sun.

Q.

Differentiate between transparent translucent and opaque objects on basis of amount of light they allow to pass through and shadow formed by them?

Q.

Which of the following object forms the most prominent shadows?

1. Opaque

2. Transparent

3. Can’t be said

4. Translucent

Q.

Light from which source of light will not have a penumbra?

1. Point source

2. The Sun

3. Wide source

4. All Sources

Q.

A sheet of plywood, a piece of muslin cloth, and a transparent glass, all of the same size and shape were placed at A one by one in the arrangement shown in Fig. Will the shadow be formed in each case? If yes, how will the shadow on the screen be different in each case?

\begin{tabular}{|l} \( S \) \\ \( C \) \\ \( R \) \\ \( E \) \\ \( A \) \\ \( N \) \end{tabular}

Q.

Why a flying airplane does not cast its shadow on earth?

Q. _______ source of light produces dark and faint shadow regions.

1. Curved
2. Small
3. Point
4. Extended

Q.

Select the luminous and nonluminous objects from the following. Candle flame, star, moon, red hot wire of heater, polished surface, a bulb, candle.

Q.

Which of the following is a luminous object?

1. Moon

2. Human

3. Stars

4. Sun

Q. Opaque objects _____ light.

1. allows
2. absorb
3. block
4. reflect

Q.

Question 17

The concave reflecting surface of a torch got rusted. What effect would this have on the beam of light from the torch?

Q. Moon emits light.

1. False
2. True

Q. We cannot see objects which do not emit light.

1. True
2. False