Chapter 5.1, Problem 3PP

Interpretation Introduction

Interpretation:

Speed of the electromagnetic wave needs to be calculated having frequency of $7.8\times {10}^{6}Hz$.

Concept introduction:

Velocity or speed is defined as the distance covered in one second by the wave. It is denoted by the letter ‘c’.

Answer to Problem 3PP

Speed of the electromagnetic wave = $3\times {10}^{8}m/s$

Explanation of Solution

All electromagnetic waves travel with the same velocity, i.e., $3\times {10}^{8}m/s$

The number of times a wave passed through a point in 1 section is known as frequency of the wave. It is denoted by the symbol $\nu$ with unit per second or Hz.

It is related to speed of light and wavelength as follows:

$\nu =\frac{c}{\lambda }$

Here, c is speed of light and $\lambda$ is wavelength.

Frequency and wavelength are independent from the velocity of electromagnetic waves.

Conclusion

Thus, speed of the electromagnetic wave = $3\times {10}^{8}m/s$