(a)[2]
State what the principle of superposition means.
(b(i))[3]
An electromagnetic wave with wavelength $0.026\,\text{m}$ in free space is directed normally onto an aluminium sheet, as shown in Fig. 4.1. The wave is reflected at the aluminium sheet and a stationary wave is formed in the region between the transmitter and the sheet. Explain how the stationary wave, including its nodes and antinodes, is formed.
(b(ii))[2]
Calculate the frequency of this electromagnetic wave.
(b(iii))[1]
State the main region of the electromagnetic spectrum to which the wave belongs.
(b(iv))[1]
Determine the distance from a node to the adjacent antinode.