Question

To calculate the frequency of an electromagnetic wave, you need to know the speed of the wave and its

A. wavelength.
B. intensity.
C. refraction.
D. amplitude.

Answer 1

And its wavelength because wavelength is the distance between two points.

Answer 2

The correct choice is

A. wavelength.

The frequency of electromagnetic wave is given as

`f=(c)/(\lambda )`

where "c" stands for speed of light whose value is well known as 3 x 10⁸ m/s and λ stands for wavelength of wave.

hence to determine the frequency, we need wavelength of wave. hence the correct choice is wavelength.