Mohit Bhasin

The quantities of heat required to raise the temperature of two solid copper spheres of radii r1 and r2 (r1 = 1.5 r2) through 1 K are in the ratio :

The solids which have the negative temperature coefficient of resistance are:

A capillary tube of radius r is immersed in water and water rises in it to a height h. The mass of the water in the capillary is 5 g. Another capillary tube of radius 2r is immersed in water. The mass of water that will rise in this tube is :

The increase in the width of the depletion region in a p-n junction diode is due to :

In a certain region of space with volume 0.2m cube, the electric potential is found to be 5V throughout. The magnitude of electric field in this region is:

Two particles of mass 5 kg and 10 kg respectively are attached to the two ends of a rigid rod of length 1 m with negligible mass. The centre of mass of the system from the 5kg particle is nearly at a distance of :

A disc of radius 2 m and mass 100 kg rolls on a horizontal floor. Its centre of mass has speed of 20 cm/s. How much work is needed to stop it?

The unit of thermal conductivity is :

A 800 turn coil of effective area 0.05 m2 is kept perpendicular to a magnetic field 5 × 10–5 T. When the plane of the coil is rotated by 90° around any of its coplanar axis in 0.1 s, the emf induced in the coil will be:

The speed of a swimmer in still water is 20 m/s.The speed of river water is 10 m/s and is flowing due east.If he is standing on the south bank and wishes to cross the river along the shortest path,the angle at which he should make his strokes wrt.north is

Body A of mass 4m moving with speed u collides with another body B of mass 2m, at rest. The collision is head on and elastic in nature. After the collision the fraction of energy lost by the colliding body A is :

Under isothermal condition, a gas at 300 K expands from 0.1 L to 0.25 L against a constant external pressure of 2 bar. The work done by the gas is (Given that 1 L bar = 100 J)