Chapter 24, Problem 1OQ

To determine

The correct statement about the electromagnetic waves travelling through vacuum.

Answer to Problem 1OQ

Option (c) and (d).

Explanation of Solution

Electromagnetic wave is the coupled propagation of electric field and magnetic field at right angles. An EM wave is the result of oscillation of a charged article.

Write the relation between frequency, wavelength and speed of wave in vacuum.

    $c=f\lambda$

Here, $c$ is the speed of light in vacuum, $f$ is the frequency of light in vacuum and $\lambda$ is the wavelength of light.

Conclusion:

It is correct that all electromagnetic waves travels at $3.0\times {10}^8\text{m}/\text{s}$ in vacuum. Thus, option (c) is correct.

It is the inherent property of an electromagnetic wave is that electric field and magnetic field is at right angles and normal to direction of wave propagation. Thus, option (d) is correct.

All electromagnetic waves cannot have same wavelength. Thus, option (a) is incorrect.

All electromagnetic waves cannot have same frequency. Thus, option (b)is incorrect.

Speed of electromagnetic wave through vacuum is independent of frequency. Thus, option (e) is incorrect.