Q. 45

# An open organ pipe has a length of 5 cm. (a) Find the fundamental frequency of vibration of this pipe. (b) What is the highest harmonic of such a tube that is in the audible range? Speed of sound in air is 340 m s^{-1} and the audible range is 20-20,000 Hz.

Answer :

Given:

Length of organ pipe

The audible range is from 20 Hz to 20,000 Hz.

The fundamental frequency of an open organ pipe is:

On substituting the respective values ,we get:

(a)The fundamental frequency of vibration of this pipe= 3.4 kHz

(b) If the fundamental frequency is 3.4 kHz, then the highest harmonic in the audible range (20 Hz – 20 kHz) is:

Required highest harmonic

Rate this question :

A source emitting a sound of frequency *v* is placed at a large distance from an observer. The source stats moving towards the observer with a uniform acceleration a. Find the frequency heard by the observer corresponding to the wave emitted just after the source starts. The speed of sound in the medium is u.

A person riding a car moving at 72 km/h sounds a whistle emitting n wave of frequency 1250 Hz, What frequency will be heard by another person standing on the road (a) in front of the car (b) behind the car? Speed of sound in air = 340 m/s.

HC Verma - Concepts of Physics Part 1Find the fundamental, first overtone and second overtone frequencies of an open organ pipe of length 20 cm. Speed of sound in air is 340 m s^{-1}.

Figure (16-E11) shows a person standing somewhere in between two identical tuning forks, each vibrating at

512 Hz. If both the tuning forks move towards right at a speed of 5.5 m s^{-1}, find the number of beats heard by the listener. Speed of sound in air = 330 m s^{-1}.

HC Verma - Concepts of Physics Part 1