16.2 Plane electromagnetic waves  (Page 5/5)

If the electric field of an electromagnetic wave is oscillating along the z -axis and the magnetic field is oscillating along the x -axis, in what possible direction is the wave traveling?

In which situation shown below will the electromagnetic wave be more successful in inducing a current in the wire? Explain.

In which situation shown below will the electromagnetic wave be more successful in inducing a current in the loop? Explain.

Under what conditions might wires in a circuit where the current flows in only one direction emit electromagnetic waves?

Shown below is the interference pattern of two radio antennas broadcasting the same signal. Explain how this is analogous to the interference pattern for sound produced by two speakers. Could this be used to make a directional antenna system that broadcasts preferentially in certain directions? Explain.

If the Sun suddenly turned off, we would not know it until its light stopped coming. How long would that be, given that the Sun is $1.496\times {10}^{11}\text{m}$ away?

What is the maximum electric field strength in an electromagnetic wave that has a maximum magnetic field strength of $5.00\times {10}^{\mathrm{-4}}\text{T}$ (about 10 times Earth’s magnetic field)?

An electromagnetic wave has a frequency of 12 MHz. What is its wavelength in vacuum?

If electric and magnetic field strengths vary sinusoidally in time at frequency 1.00 GHz, being zero at $t=0$ , then $E=E_0\text{sin}2\pi ft$ and $B=B_0\text{sin}2\pi ft$ . (a) When are the field strengths next equal to zero? (b) When do they reach their most negative value? (c) How much time is needed for them to complete one cycle?

The electric field of an electromagnetic wave traveling in vacuum is described by the following wave function:
$\overrightarrow{E}=\left(5.00\text{V/m}\right)\text{cos}\left[kx-\left(6.00\times {10}^9{\text{s}}^{\mathrm{-1}}\right)t+0.40\right]\widehat{j}$
where k is the wavenumber in rad/m, x is in m, t is in s.
Find the following quantities:
(a) amplitude
(b) frequency
(c) wavelength
(d) the direction of the travel of the wave
(e) the associated magnetic field wave

A plane electromagnetic wave of frequency 20 GHz moves in the positive y -axis direction such that its electric field is pointed along the z -axis. The amplitude of the electric field is 10 V/m. The start of time is chosen so that at $t=0$ , the electric field has a value 10 V/m at the origin. (a) Write the wave function that will describe the electric field wave. (b) Find the wave function that will describe the associated magnetic field wave.

The following represents an electromagnetic wave traveling in the direction of the positive y -axis: $\begin{array}{c}{E}_x=0;E_y=E_0\text{cos}\left(kx-\omega t\right);E_z=0\hfill \\ B_x=0;B_y=0;B_z=B_0\text{cos}\left(kx-\omega t\right)\hfill \end{array}$ .
The wave is passing through a wide tube of circular cross-section of radius R whose axis is along the y -axis. Find the expression for the displacement current through the tube.