Answer
See work below.
Work Step by Step
On page 907, in section 31-9, the frequency is stated as 42.58 MHz for a 1.0 T field.
Find the wavelength.
$$\lambda=\frac{c}{f}=\frac{2.998\times10^8m/s}{42.58\times10^6Hz}=7.041m$$
These are radio waves.
