144 views

The magnetic field along the propagation direction inside a rectangular waveguide with the cross-section shown in the figure is

$$H_Z=3\:\cos(2.094\times10^2x)\:\cos(2.618\times10^2y)\:\cos(6.283\times10^{10}t-\beta z)$$

The phase velocity $v_p$ of the wave inside the waveguide satisfies

1. $v_p\gt c$
2. $v_p=c$
3. $0\lt v_p\lt c$
4. $v_p=0$