The speed of sound waves in a mixture of helium and neon at 300 K and at a pressure of 76 cm of Hg was found to be 758 m/sec. The densities of helium and neon are respectively 0.1785 and 0.8999 g/litre and γ of mixture is 1.667. What is the ratio of He and Ne in the mixture?


Correct option is






Given, density of He = 0.1785 g/litre, density of Ne = 0.8999 g/litre. 

Let the ratio be x:1.


Solving for x, we get the ratio 5:1.



In an experiment, it was found that a tuning fork and a sono-meter emitting its fundamental note, gave 5 beats per second both when the length of the wire was 1 metre and 1.05 metre. The velocity of transverse waves in the sono-meter wire is:


A slab of mass m is released from a height h0 from the top of a spring S’ of force constant  K. The maximum compression x of the spring is given by the equation:



A bob of mass m is oscillating as a simple pendulum with maximum amplitude θm. What is the maximum tension in the string?


A certain amount of acoustic energy is emitted in a uniform hemispherical pattern from a point source. At a distance of 5 m form the source the intensity is 5 W/m2. At a distance of 15 m the intensity will be:


 A 10 W source of sound of frequency 1000 Hz sends out waves in air. The displacement amplitude at a distance of 10 m from source will be: (Given velocity of sound = 350 m/s and density of air = 1.29 kg/m3)


The air in a closed tube 34 cm long is vibrating with 2 nodes and 2 antinodes and the temperature is 51oC. What is the wavelength of waves produced in air outside the tube when the temperature of air is 16oC?


The fundamental frequency of a longitudinal vibrating of a rod clamped at its centre is 1500 Hz. If the mass of the rod is 96 g the increase in its total length produced by a stretching force of 10 kg weight will be:


If there are three sources of sound of equal intensity with frequencies 300, 301 and 302, the number of beats heard per second will be:


The speed of sound waves in dry air at NTP is 332 m/sec. Assuming air to be composed of oxygen and nitrogen in the ratio 1:4 and the densities of oxygen and nitrogen at NTP to be in the ratio 8:7, the velocity of sound in oxygen will be equal to:


The number of possible overtones of air column in a closed pipe of length 83.2 cm and of diameter 6 cm whose frequencies lie below 1000 Hz will be [velocity of sound = 340 m/s]: