Question

Find out the ratio of the velocity of sound in helium and in nitrogen gases at 300 K temperature. Molecular weights of helium and nitrogen are 4 and 28 respectively.

Solution

Correct option is

2.9

 

The speed of sound in a gas is, 

Where T is absolute temperature of the gas and M is molecular weight of the gas. The speed of sound in helium is 

                           

And that in nitrogen is  

                        

                     

We know that for a mono-atomic gas (as He) the value of γ is 5/3, and for a diatomic gas (as N) is 7/5.

Given: MN = 28 and MHe = 4.  

                    

SIMILAR QUESTIONS

Q1

A particle, with restoring force proportional to displacement and damping force proportional to velocity is subjected to a force F sin ωt. If the amplitude of the particle is maximum at ω = ω1 and its energy is maximum at ω = ω2, then (ω0 is the angular frequency of natural oscillations of the particle)

Q2

A vehicle with a horn of frequency n is moving with a velocity of 30 ms–1in a direction perpendicular to the straight line joining the observer and the vehicle. The observer perceives the sound to have a frequency (n + n1). If the sound velocity in air is 300 ms–1 

Q3

Two springs of constants k1 and k2 have equal highest velocities while executing S.H.M. If their masses are equal, the ratio of their amplitudes will be

Q4

The velocity of sound is the greatest is

Q5

The speed of a wave in a medium is 960 m/s. If 3600 waves are passing through a point in the medium in  minute, then calculate the wavelength.

Q6

What is the frequency of radio waves transmitted by a station, if the wavelength of three waves is 300 meter?

Q7

At a pressure of 105N/m2 the volume strain of water is  Calculate the speed of sound in water. (Density of water = kg/m3).

Q8

At normal temperature and pressure the speed of sound in air is 332 m/s. What will be the speed of sound in hydrogen (i) at normal temperature and pressure, (ii) at 546oC temperature and 3 atmospheric pressure? (Air is 16 times heavier than hydrogen).

Q9

The speed of sound in oxygen is 635 m/s. Find out the speed of sound in a mixture of hydrogen and oxygen in which the ratio of hydrogen and oxygen volumes is 4:1.

Q10

At what temperature will the speed of sound in air be double of its speed at 57oC?