Wednesday, 10 September 2014


1.    Write down the following parts of the electromagnetic spectrum in order of decreasing wavelength.

Radar, Visible light, Infra-red, Microwave, Ultra-violet, Gamma radiation, X-rays, TV, Radio, UHF.

2. Which of the waves has the (a) highest frequency?    (b) lowest energy?

3. List three properties common to all electromagnetic waves.

4. (a) The frequency of ultra-violet is 10 000 million  MHz, what is its wavelength?
(b) Radio 4 is broadcast on 200 kHz, what is the wavelength? 
(c) By looking at a chart of the electromagnetic spectrum you should find that the wavelength of visible light (orange) is around 0.6 micrometres
What is the frequency of orange light?

5. In each case below write down a type of radiation which
(a) will cause fluorescence
(b) is emitted by a hot object
(c) can pass through lead
(d) can be detected by the eye
(e) can be diffracted by a hill                                                            
(f) causes damage to the retina
(g) is used for satellite communications
(h) can be use to kill bacteria.

6.      Explain briefly how the following radiations are produced
  (a)    Gamma
  (b)    X-rays
  (c)    Infra-red
  (d)    Radio waves