Topic Menu

Cyber-chess a chess instruction site

GCSE level questions on light

Q4. Visible light is used for communications.

Name two other parts of the electromagnetic spectrum are used for communications.

Microwaves and radiowaves.

[2 marks]

(b) The appearance of visible light can change when it interacts with different objects.

Complete the sentences below selecting your answers from this box of words:

absorbed
reflected
refracted
transmitted
Each answer may be used once, more than once or not at all.

When white light is incident on a green filter, only green light passes through the filter. This is because green light is transmitted by the filter. All other colours of light are absorbed by the filter. When red light shines on a blue object the red light is absorbed.

[3 marks]

(c) The diagram shows a spotlight containing a convex lens. A cyan filter is placed in front of the spotlight. The spotlight is directed at a yellow object in a darkened room.

Explain why the yellow object appears green.

The cyan filter only allows green and blue light through - absorbing all others.

The yellow object only reflects red and green light - absorbing all others.

The yellow object can therefore only reflect green light, as thiss is the only light falling on it that it does not absorb.

[3 marks]

 

(Total 8 marks)