In one metre long open pipe what is the harmonic of resonance obtained with a tuning fork of frequency 480 Hz : (Velocity of sound: 320 m/s)

(1) First

(2) Second

(3) Third

(4) Fourth

In a resonance pipe the first and second resonances are obtained at depths 22.7 cm and 70.2 cm respectively. What will be the end correction 

(1) 1.05 cm

(2) 115.5 cm

(3) 92.5 cm

(4) 113.5 cm

An open tube is in resonance with string (frequency of vibration of the tube is n₀). If the tube is dipped in water so that 75% of the length of the tube is inside water, then the ratio of the frequency of tube to string now will be :

(1) 1

(2) 2

(3) $\frac{2}{3}$

(4) $\frac{3}{2}$

A source of sound of frequency 450 cycles/sec is moving towards a stationary observer with 34 m/sec speed. If the speed of sound is 340 m/sec, then the apparent frequency will be 

(1) 410 cycles/sec

(2) 500 cycles/sec

(3) 550 cycles/sec

(4) 450 cycles/sec

The frequency of a whistle of an engine is 600 cycles/sec is moving with the speed of 30 m/sec towards an observer. The apparent frequency will be (velocity of sound = 330 m/s) 

(1) 600 cps

(2) 660 cps

(3) 990 cps

(4) 330 cps

An observer moves towards a stationary source of sound of frequency n. The apparent frequency heard by him is 2n. If the velocity of sound in air is 332 m/sec, then the velocity of the observer is :

(1) 166 m/sec

(2) 664 m/sec

(3) 332 m/sec

(4) 1328 m/sec

A person feels 2.5% difference of frequency of a motor-car horn. If the motor-car is moving to the person and the velocity of sound is 320 m/sec, then the velocity of car will be 

(1) 8 m/s (approx.)

(2) 800 m/s

(3) 7 m/s

(4) 6 m/s (approx.)

A source of sound emitting a note of frequency 200 Hz moves towards an observer with a velocity v equal to the velocity of sound. If the observer also moves away from the source with the same velocity v, the apparent frequency heard by the observer is 

(1) 50 Hz

(2) 100 Hz

(3) 150 Hz

(4) 200 Hz

A source of sound is traveling towards a stationary observer. The frequency of the sound heard by the observer is three times the original frequency. The velocity of sound is v m/sec. The speed of the source will be :

(1) $\frac{2}{3}v$

(2) v

(3) $\frac{3}{2}v$

(4) 3v

A sound source is moving towards a stationary observer with 1/10 of the speed of sound. The ratio of apparent to real frequency is : 

(1) 10/9

(2) 11/10

(3) (11/10)²

(4) (9/10)²