A source of sound of frequency n is moving towards a stationary observer with a speed S. If the speed of sound in air is V and the frequency heard by the observer is n₁, the value of n₁/n is 

(1) (V + S)/V

(2) V/(V + S)

(3) (V – S)/V

(4) V/(V – S)

An observer is moving away from the source of the sound of frequency 100 Hz. His speed is 33 m/s. If the speed of sound is 330 m/s, then the observed frequency is :

(1) 90 Hz

(2) 100 Hz

(3) 91 Hz

(4) 110 Hz

An observer standing at the station observes frequency 219 Hz when a train approaches and 184 Hz when train goes away from him. If velocity of sound in air is 340 m/s, then velocity of train and actual frequency of whistle will be 

(1) $15.5m{s}^{-1},200Hz$

(2) $19.5m{s}^{-1},205Hz$

(3) $29.5m{s}^{-1},200Hz$

(4) $32.5m{s}^{-1},205Hz$

A boy is walking away from a wall towards an observer at a speed of 1 metre/sec and blows a whistle whose frequency is 680 Hz. The number of beats heard by the observer per second is (Velocity of sound in air = 340 metres/sec)
1. Zero
2. 2
3. 8
4. 4

The driver of a car traveling with speed 30 meters per second towards a hill sounds a horn of frequency 600 Hz. If the velocity of sound in air is 330 meters per second, the frequency of the reflected sound as heard by the driver is :

1. 720 Hz

2. 555.5 Hz

3. 550 Hz

4. 500 Hz

A source of sound is travelling with a velocity 40 km/hour towards the observer and emits the sound of frequency 2000 Hz. If the velocity of sound is 1220 km/hour, then what is the apparent frequency heard by an observer 

1. 2210 Hz

2. 1920 Hz

3. 2068 Hz

4. 2086 Hz

A source of sound and listener are approaching each other with a speed of 40 m/s. The apparent frequency of note produced by the source is 400 cps. Then, its true frequency (in cps) is (velocity of sound in air = 360 m/s) 

1. 420

2. 360

3. 400

4. 320

A siren emitting sound of frequency 500 Hz is going away from a static listener with a speed of 50 m/sec. The frequency of sound to be heard, directly from the siren, is :

(1) 434.2 Hz

(2) 589.3 Hz

(3) 481.2 Hz

(4) 286.5 Hz

A man sitting in a moving train hears the whistle of the engine. The frequency of the whistle is 600 Hz 

1. The apparent frequency as heard by him is smaller than 600 Hz

2. The apparent frequency is larger than 600 Hz

3. The frequency as heard by him is 600 Hz

4. None of the above

A whistle of frequency 500 Hz tied to the end of a string of length 1.2 m revolves at 400 rev/min. A listener standing some distance away in the plane of rotation of whistle hears frequencies in the range (speed of sound = 340 m/s) 

(1) 436 to 586

(2) 426 to 574

(3) 426 to 584

(4) 436 to 674