Physics Test - ...

A steel ball of mass 60 g falls from a height 0.8 m on the horizontal surface of a massive slab. The coefficient of restitution between the ball and the slab is e = 0.4; the total momentum imparted to the slab by the ball after numerous bounces is

A sphere with some cavity has outer radius R. It rolls down an inclined plane without slipping and attains a speed v at the bottom. When this sphere slides down without rolling on the frictionless inclined plane of same height its speed at the bottom is .$\frac{5v}{4}$ The radius of gyration of the sphere is

A standard cell of emf E₁ = 6 V and negligible internal resistance is connected to the terminals of a potentiometer of resistance R = 20 Ω. A storage battery of emf E and negligible internal resistance is connected to a galvanometer as shown.

On moving the jockey along AB, when AN is 16 ohms, the galvanometer shows null deflection. The emf of the storage battery E is

An alternating voltage having frequency of 50 cycles/sec and maximum voltage 220 V is supplied to a circuit containing a pure inductance of 0.02 H and a pure resistance of 10 Ω in series. The value of maximum current in circuit is-

The antenna current of an AM transmitter is 8 A when only carrier wave is sent but the current increases to 8.88 A when the carrier wave is sinusoidally modulated. The percentage of modulation is

Figure shows the plot of a potential energy function of a conservative system U versus x. Which of the following statements is correct ?

If a magnet is suspended at an angle of 30° to the magnetic meridian, and the dip needle shows 45° to the horizontal, the real dip is

The radius of a sphere is measured to be (2.1 ± 0.05) cm. Calculate the surface area (in cm²) with error limits.

When an UV light of 10¹⁵ Hz and intensity 2 W/m² is directed at a metal surface, photoelectrons emitted were found to have a maximum kinetic energy of 1.6 eV. If the work functions for different materials are as follows: Potassium 2.2 eV, Sodium 2.3 eV, Lithium 2.5 eV and Calcium 3.2 eV, identify the metal in the given problem.

A circular disc of radius r and thickness r/6 has moment of inertia I about an axis passing through its centre and perpendicular to its plane. It is melted and recasted to a solid sphere. The moment of inertia of the sphere about its diameter as axis of rotation is