Physics Mock Test

The wave nature of electrons was experimentally verified by

A satellite is moving with a constant speed v in a circular orbit about the earth. An object of mass m is ejected from the satellite such that it just escapes from the gravitational pull of the earth. At the time of its ejection, the kinetic energy of the object is

A seconds pendulum is mounted in a rocket. Its period of oscillation decreases when the rocket __________.

The magnetic field at a distance r from a long wire carrying current i is 0.4 Tesla. The magnetic field at a distance 2r is: CBSE PMT 1992

Two moles of ideal helium gas are in a rubber balloon at 30°C. The balloon is fully expandable and can be assumed to require no energy in its expansion. The temperature of the gas in the balloon is slowly changed to 35°C. The amount of heat required in raising the temperature is nearly (take R = 8.31 J/mol-K)

A 40 mF capacitor is connected to a 200 V. 50 Hz ac supply. The rms value of the current on the circuit is, nearly: NEET 2020

In an electromagnetic wave in free space the root mean square value of the electric field is E_rms = 6 V/m. The peak value of the magnetic field is

A ball of mass 150 g moving with an acceleration 20 m/s² is hit by a force, which acts on it for 0.1 s. The impulsive force is __________. CBSE AIPMT 1996

Focal length of a convex lens of refractive index 1.5 is 2 cm. Focal length of lens when immersed in a liquid of refractive index 1.25 will be ________. CBSE AIPMT 1988

A student is performing the experiment of resonance column. The diameter of the column tube is 4 cm. The frequency of the tuning fork is 512 Hz. The air temperature is 38° C in which the speed of sound is 336 m/s. The zero of the meter scale coincides with the top end of the resonance column tube. When the first resonance occurs, the reading of the water level in the column is