Two cars moving in opposite directions approach each other with speed of 22m/s and 16.5 m/s respectively. The driver of the first car blows a horn having a frequency 400 Hz. The frequency heard by the driver of the second car is [velocity of sound 340m/s]

1. 350Hz

2. 361Hz

3. 411Hz

4. 448Hz

4.0 g of a gas occupies 22.4 L at NTP. The specific heat capacity of the gas at constant volume is 5.0 J K^-1mol^-1. If the speed of sound in this gas at NTP is$952 m{s}^{-1}$, then the heat capacity at constant pressure is: (Take gas constant R=8.3 JK^-1mol^-1)

(1) 8.0 JK^-1mol^-1
 

(2) 7.5 JK^-1mol^-1
 

(3) 7.0 JK^-1mol^-1
 

(4) 8.5 JK^-1mol^-1

A speed motorcyclist sees a traffic jam ahead of him. He slows down to 36km/h. He finds that traffic has eased and a car moving in front of him at 18km/h is honking at a frequency of 1392Hz. If the speed of sound is 343m/s, the frequency of the honk as heard by him will be 
1. 1332Hz
2. 1372Hz
3. 1412Hz
4. 1454Hz 

A wave travelling in the positive x-direction having maximum displacement along y-direction as 1m, wavelength 2π m and frequency of 1/π Hz is represented by

(1) y=sin(x-2t)

(2) y=sin(2πx-2πt)

(3) y=sin(10πx-20πt)

(4) y=sin(2πx+2πt)

If we study the vibration of a pipe open at both ends. then the following statements is not true

(1) Open end will be anti-node

(2) Odd harmonics of the fundamental frequency will be generated

(3) All harmonics of the fundamental frequency will be generated

(4) Pressure change will be maximum at both ends

Two sources of sound placed close to each other, are emitting progressive waves given by

${\mathrm{y}}_1$=4 sin 600$\mathrm{\pi t}$ and ${\mathrm{y}}_2$=5 sin 608 $\mathrm{\pi t}$

An observer located near these two sources of sound will hear

(a)4 beats per second with intensity ratio 25:16 between waxing and waning

(b) 8 beats per second with intensity ratio 25:16 between waxing and waning

(c) 8 beats per second with intensity ratio 81:1 between waxing and waning

(d) 4 beats per second with intensity ratio 81:1 waxing and waning

The equation of a simple harmonic wave is 

given by 

          $\mathrm{y}=3 \sin \frac{\mathrm{\pi }}{2}(50\mathrm{t}-\mathrm{x})$

where x and y are in meters and t is in 

seconds. The ratio of maximum particle 

velocity to the wave velocity is

(1) $2\mathrm{\pi }$

(2) $\frac{3}{2}\mathrm{\pi }$

(3) $3\mathrm{\pi }$

(4) $\frac{2}{3}\mathrm{\pi }$

A train moving at a speed of 220 ${\mathrm{ms}}^{-1}$ towards a stationary object, emits a sound of frequency 1000 Hz. Some of the sound reaching the object gets reflected back to the train as an echo. The frequency of the echo as detected by the driver of the train is
(speed of sound in air is 330 ${\mathrm{ms}}^{-1}$)
1. 3500Hz
2. 4000Hz
3. 5000Hz
4. 3000Hz