A monoatomic gas is suddenly compressed to (1/8) of its initial volume adiabatically. The ratio of its final pressure to the initial pressure is : (Given the ratio of the specific heats of the given gas to be 5/3)

• 32

• 40/3

• 24/5

• 8

A Carnot engine takes heat from a reservoir at 627° C and rejects heat to a sink at 27°C. Its efficiency will be

• 3/5

• 1/3

• 2/3

• 200/209

A tuning fork A produces 4 beats/s with another tuning fork B of frequency 320 Hz. On filing one of the prongs of A,4 beats/s are again heard when sounded with the same fork B. Then, the frequency of the fork A before filing is

• 328 Hz

• 316 Hz

• 324 Hz

• 320 Hz

When the length of the vibrating segment of a sonometer wire is increased by 1%, the percentage change in its frequency is

• $\frac{100}{101}$

• $\frac{99}{100}$

• 1

• 2

15.

The sprinkling of water reduces slightly the temperature of a closed room because

• temperature ofwater is less than that of the room

• specific heat of water is high

• water has large latent heat of vaporisation

• water is a bad conductor of heat

The equation of a simple harmonic wave is given by $\mathrm{y} = 5 \sin \frac{\mathrm{\pi }}{2} \left(100\mathrm{t} - \mathrm{x}\right)$, where x and y are in metre and time is in second. The period of the wave in second will be

• 0.04

• 0.01

• 1

• 5

The loudness and pitch of a sound note depends on

• intensity and frequency

• frequency and number of harmonics

• intensity and velocity

• frequency and velocity

A rectangular vessel when full ofwater, takes 10 min to be emptied through an orifice in its bottom. How much time will it take to be emptied when half filled with water ?

• 9 min

• 7 min

• 5 min

• 3 min

If there were no gravity, which of the following will not be there for a fluid ?

• Viscosity

• Surface tension

• Pressure

• Archimedes' upward thrust

The term liquid crystal refers to a state that is intermediate between

• crystalline solid and amorphous liquid

• crystalline solid and vapour

• amorphous liquid and its vapour

• a crystal immersed in a liquid