The diagram above represents a transverse electromagnetic wave travelling with speed 3.0 x 108ms-1. What is the frequency of the wave.
A
3.0 x 107Hz
B
9.0 x 107Hz
C
1.0 x 109Hz
D
3.0 x 109Hz
Verified Correct Answer: D.
Physical Principles & Numerical Solution
The frequency f = V/λ,
Where λ = wavelength
From the above, the distance OA = one wavelength; AB = one wave length and BC = one wavelength.
=> OC = 3 wavelength = 3λ
∴3λ = 0.3M
λ = 0.3/3
= 0.1m
∴ f = V/λ = (3.0 x 108) / 0.1
= 3.0 x 109Hz
Source: Official Exam / Past Question Archive