Shadow

Q.

The formation of shadows, suggests that light travels in

1. vacuum

2. straight lines

3. dark rooms

4. none of these

Q.

Can a shadow be formed without a screen?

Q.

Objects which allow a part of the light falling on them to pass through them are?

1. Luminous

2. Transparent

3. Translucent

4. Opaque

Q.

A shadow is seen only during day time

1. True
2. False

Q.

Give reason

We get both the umbra and the penumbra regions in the shadow of an opaque object when we use a finite source of light.

Q.

Name the things other than a source of light and opaque object required to see the shadow.

Q.

A dark patch formed behind an opaque body, when it is placed in the path of light is called___________.

Q.

To form a shadow, the things required are: a source of light, an opaque object and a screen.

1. True
2. False

Q.

Is it possible to see a shadow in absolute darkness?

Q.

Do you observe a shadow when there is just a source of light and nothing else in a room?

Q. During a partial lunar eclipse, the moon is in the _____ region of Earth's shadow.

1. Umbra
2. Penumbra
3. Antumbra
4. Umbra and Penumbra

Q. Two torches are switched on one by one upon a football like the below figure. The position of the shadow for each torch on the screen will be different.

1. True
2. False

Q. In the diagram shown, what is the letter A and letter B pointing towards?

1. A-Umbra, B-Penumbra
2. A-Penumbra, B-Umbra
3. A-Umbra, B-Antumbra
4. A-Penumbra, B-Antumbra

Q. Whenever light falls on an opaque object, a shadow will always be observed in the background.

1. True
2. False

Q.

Explain umbra?

Q.

The shadow of a flying aeroplane cannot be seen on the earth. Explain why?