(a(i))[2]
On Fig. 7.1, write the names of the radiations in the two other parts of the electromagnetic spectrum.
(a(ii))[1]
State one application of $$-rays.
(a(iii))[2]
State whether the radio waves or the $$-rays, if either, reach the Earth’s atmosphere first. Give a reason for your answer.
(b(i))[2]
Use the graph in Fig. 7.2 to find the time interval between pulses.
(b(ii))[2]
Determine the frequency of the pulses shown in Fig. 7.2.