Question

In which of the following cases time period of a wave is maximum?

• A. When the frequency is f
• B. When the frequency is f/2
• C. When the frequency is 2f
• D. When the frequency is f/4

Answer 1

The correct option is D

When the frequency is f/4

We know that $T=\frac{1}{f}$
$\Rightarrow$ Smaller the value of frequency, more is the time period.
From the given option, $\frac{f}{4}$ is the smallest frequency.
So, f = f/4 we get, T = $\frac{1}{f/4}$ becomes,

T = $\frac{4}{f}$

This leads to maximum time period because of greater numerator value compared to other cases where frequency is f, 2f and f/2.