Answer
a. 2.00 m.
b. 1.00 m.
Work Step by Step
a. The nodal planes of the electric field are $\lambda/2$ apart.
$$\lambda/2 =\frac{c}{2f}=\frac{3.00\times10^{8}m/s}{(2)(75.0\times10^{6}Hz)}=2.00m$$
b. The nodal planes of the magnetic field are separated by a distance $\lambda/2$ and are midway between the nodal planes of the electric field.
The distance between a nodal plane of $\vec{E}$ and one of $\vec{B}$ is one-quarter of a wavelength.
$$\lambda/4 =\frac{c}{4f}=\frac{3.00\times10^{8}m/s}{(4)(75.0\times10^{6}Hz)}=1.00m$$
