Question

A resonance air column of length 20 cm resonates with a tuning fork of frequency 250 Hz. The speed of sound in air is

• A. 300 m/s
• B. 200 m/s
• C. 150 m/s
• D. 75 m/s

Answer 1

Answer: (B)

200 m/s

Answer 2

For closed pipe$n_{1} = \frac{v}{4l} \Rightarrow 250 = \frac{v}{4 \times 0.2}$

$\Rightarrow v = 200m/s$