Question

Radio waves and microwaves are similar because they both have

a. high frequencies and high energy.
b. low frequencies and low energy.
c. high frequencies and low energy.
d. low frequencies and high energy

Answer 1

The correct answer is

b. low frequencies and low energy.

In fact, microwaves and radio waves have frequency up to
`10^(10)-10^(11) Hz`, which are really low compared, for instance, to the frequency of gamma rays (
`10^(20) Hz`). Moreover, the energy of an electromagnetic wave is directly proportional to its frequency:

`E=hf`

where h is the Planck constant and f the frequency; therefore, low frequency means also low energy.