# GCSE Science Unit 1 Physics

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Explain what is meant by an intense coherent laser beam.
The waves have the same frequency and wavelength, and the waves have low divergence.
1 of 10
Describe the job of a multiplexer.
To separate the signal into several outputs.
2 of 10
Noah's skin is naturally darker than Aiden's, he thinks this may reduce his skin cancer risk from ultraviolet waves. Is he correct and why?
Yes, because darker skin absorbs more ultraviolet radiation.
3 of 10
The ozone layer protects the earth from ultraviolet radiation. Environmental pollution from CFCs had depleted the ozone layer. Explain why people are concerned about this.
More UV radiation reaches the Earth so more potential danger to human health increases.
4 of 10
Write about one of the possible health risks from using mobile phones and suggest how this risk can be reduced.
The microwaves in phones can cause cancer cells. The risk can be reduced by using a remote ear piece.
5 of 10
When ice melts, the temperature does not change. Explain why.
Because energy is being used to break forces or bonds between molecules rather than increasing the temperature.
6 of 10
What parts are there to the electromagnetic spectrum?
Gamma rays, x-rays, UV, visible light, IR, microwaves, radio waves.
7 of 10
Describe how data is stored on a compact disc and how it's data is read by a laser.
Pits store digital information, and when a laser/light is shone onto a surface of a CD the light reflects from pits, the reflected pulses converted into electrical signal.
8 of 10
Explain what is meant by intense and coherent.
Intense: lots of energy in a small place. Coherent: same frequency.
9 of 10
What is the equation for the speed of a wave?
Wave speed = frequency x wavelength
10 of 10

## Other cards in this set

### Card 2

#### Front

Describe the job of a multiplexer.

#### Back

To separate the signal into several outputs.

### Card 3

#### Front

Noah's skin is naturally darker than Aiden's, he thinks this may reduce his skin cancer risk from ultraviolet waves. Is he correct and why?

### Card 4

#### Front

The ozone layer protects the earth from ultraviolet radiation. Environmental pollution from CFCs had depleted the ozone layer. Explain why people are concerned about this.

### Card 5

#### Front

Write about one of the possible health risks from using mobile phones and suggest how this risk can be reduced.