Question

The frequency of $3^{rd}$ harmonic in an open organ pipe of length 33 cm. If the velocity of sound is 330 m/s, is

• A. 750 Hz
• B. 2000 Hz
• C. 1500 Hz
• D. 2500 Hz

Answer 1

The correct option is C 1500 Hz

Given:

The length of the organ pipe l is, 33 cm

Velocity of sound v is, 330 m/s

To find:

The frequency of 3rd harmonic, n

where, $p=3$

Solution:

From the equation,

$n=\frac{pv}{2l}$

$n=\frac{3\left(330\right)}{2\left(33\right)\left({10}^{-2}\right)}$

$n=1500Hz$

so, the correct answer is option (c)