1. (a) All radiations in the electromagnetic spectrum travel at a speed of 3 x 10⁸m/s in space.

Calculate the wavelength of the microwaves with the longest wavelength.

 

 

 

 

 

(b) Microwaves are part of the electromagnetic spectrum.
The diagram below shows the electromagnetic spectrum arranged been omitted. Name the radiations P and Q.

 

 

 

(c) In which part of the spectrum do the waves have the highest energy?

(d) Name the colours of visible light from lowest to highest wavelength

2. An optical fibre is used to carry a telephone message to the USA from Scotland. It travels 5000 km. The light signals travel at a speed of 2 x 10⁸ m/s. How long will this take?

3. X-rays travel at the speed of light. They have a range of frequencies from 3 x 10¹⁶ Hz to 3 x 10¹⁹ Hz.

Calculate the range of wavelengths that correspond to X-rays

4. Different types of radiation are used to detect and treat illnesses and injuries.
Four of these radiations are

(a) What type of radiation is used to treat skin conditions such as acne?

(b)
(i) State one medical use of X-rays.
(ii) What can be used to detect X-rays?
(c) Colour photographs called thermograms are used to find the temperature variation in a patient’s body.
Name the radiation used to make thermograms.

(d)

Explain why people need to be protected from overexposure to ultraviolet radiation.