Physics Test 11...

Orbital radius of a satellite S of earth is four times that of a communication satellite C. Period of revolution of S is :-

Three identical solid spheres move down three inclines A, B and C–all of the same dimensions. A is without friction, the friction between B and a sphere is sufficient to cause rolling without slipping, the friction between C and a sphere causes rolling with slipping. The kinetic energies of A, B, C at the bottom of the inclines are E_A, E_B, E_C.

A rectangular film of liquid is extended from (4cm × 2cm) to (5cm × 4cm). If the work done is 3×10^–4J. the value of the surface tension of the liquid is :

A rifle bullet of mass 0.1 kg strikes and embeds itself in a block of mass 0.9 kg. The block rests on a horizontal frictionless table and is attached to a spring as shown in fig. The impact compresses the spring by 0.2m. If a force of 1N compresses the spring by 2cm, calculate initial velocity of bullet.

An organ pipe closed at one end has fundamental frequency of 1500 Hz. The maximum number of overtones generated by this pipe which a normal person can hear is

A racing car moving towards a cliff sounds its horn. The driver observes that the sound reflected from the cliff has a pitch one octave higher than the actual sound of the horn. If v is the velocity of sound, the velocity of the car will be :-

A 2 kg copper block is heated to 500°C and then it is placed on a large block of ice at 0°C. If the specific heat capacity of copper is 400 J/kg/°C and latent heat of fusion of water is 3.5 × 10⁵ J/kg. The amount of ice that can melt is :

Two moles of helium gas are taken along the path ABCD (as shown in figure). The work done by the gas is 

Certain quantity of water cools from 70°C to 60°C in the first 5 minutes and to 54°C in the next 5 minutes. The temperature of the surroundings is :-

Cooling rate of a sphere of 600 K at external environment (200 K) is R. When the temperature of sphere is reduced to 400 K then cooling rate of the sphere becomes :