Question

A sound wave causes the density of air at a place to oscillate $1200$ times in $2\text{minutes}$. Find the time period of the wave.

• A. $10\text{s}$
• B. $0.1\text{s}$
• C. $20\text{s}$
• D. $0.2\text{s}$

Answer 1

The correct option is B $0.1\text{s}$

Number of oscillations in $2\text{minutes}=1200$

So,
Number of oscillations in $1\text{s}=\frac{1200}{2\times 60}=10$

$\therefore f=10\text{Hz}$

Now, $T=\frac{1}{f}=\frac{1}{10}=0.1\text{s}$