List of top Physics Questions

If the differences between the specific heat capacities at constant pressure and constant volume of hydrogen and another gas are in the ratio 16 : 1, then the other gas is:
If the threshold wavelength of light for photoelectric emission to take place from a metal surface is \( 6250 \, \text{\AA} \), then the work function of the metal is (Planck's constant \( = 6.6 \times 10^{-34} \, \text{Js} \))
A force of 10 N acts on a body of mass 2 kg in the direction of motion of the body. If the velocity of the body at a time \( t = 0 \) is \( 13\,{ms}^{-1} \), then the velocity of the body at time \( t = 3\,{s} \) is
The maximum magnetic field produced by a current of 12 A passing through a copper wire of diameter 1.2 mm is
For transmitting a signal of frequency 1000 kHz, the minimum length of the antenna is
A thin uniform circular disc rolls with a constant velocity without slipping on a horizontal surface. Its total kinetic energy is
If the intensities of two interfering light waves in a medium are I and 4I, then the maximum and minimum intensities are respectively:
A wire of resistance \( R \) is bent in the form of a circular loop. Two points on the circle separated by a quarter circumference are connected to a battery of emf \( E \) and negligible internal resistance. The heat generated in the wire per second is:
If the internal energy of 3 moles of a gas at a temperature of 27 °C is 2250R, then the number of degrees of freedom of the gas is (R - Universal gas constant)
A wire of length 20 cm is placed horizontally on the surface of water and is gently pulled up with a force of $1.456 \times 10^{-2}\, N$ to keep the wire in equilibrium. The surface tension of water is
The work done to take a body of mass 100 kg to the top of a building of height 20 m is (Acceleration due to gravity = 10 m s\textsuperscript{-2})
If the velocity at the maximum height of a projectile projected at an angle of \(45^\circ\) is \(20 \, \text{m/s}\), then the maximum height reached by the projectile is:
A body is dropped freely from a height of 8 m from the ground. If the coefficient of restitution between the body and the ground is 0.5, then the maximum height reached by the body after second impact with the ground is
The equation for 2310Ne nucleus which decays by β-emission is:
If the wavelengths of maximum intensity of radiation emitted by two black bodies A and B are \( 0.5 \, \mu\text{m} \) and \( 0.1 \, \text{mm} \) respectively, then ratio of the temperatures of the bodies A and B is
Two bodies A and B of masses 20 kg and 5 kg respectively are at rest. Due to the action of a force of 40 N separately, if the two bodies acquire equal kinetic energies in times \( t_A \) and \( t_B \) respectively, then \( t_A : t_B = \)
The energy stored in a capacitor of capacitance \( 10 \, \mu\text{F} \) when charged to a potential of 6 kV is
A closed vessel contains a gas at a pressure $P$. If 50% of the mass of the gas is removed and rms speed of the gas molecules is increased by 20%, then the pressure of the remaining gas is
A horizontal telegraph wire of length $30~\text{m}$ fell from a height of $20~\text{m}$. If resistance is $40~\Omega$ and horizontal component of Earth’s magnetic field is $2 \times 10^{-5}~\text{T}$, the induced current is
If a wheel with 24 metallic spokes each \( 40 \) cm long is rotated with a speed of \( 180 \) rev/min in a plane normal to the horizontal component of Earth's magnetic field, the emf induced between the axle and the rim of the wheel is \( E \). If the number of spokes is made \( 12 \) and the wheel is rotated with a speed of \( 90 \) rev/min in the same field, the induced emf is:
If the angular momenta of electrons in two orbits of hydrogen atom are \( \frac{h}{\pi} \) and \( \frac{1.5h}{\pi} \), then the ratio of velocities of electrons in these two orbits is
(h – Planck’s constant)
At absolute zero temperature, an intrinsic semiconductor behaves as
If the maximum velocity and maximum acceleration of a particle executing simple harmonic motion are respectively \( 5 \, \text{m s}^{-1} \) and \( 10 \, \text{m s}^{-2} \), then the time period of oscillation of the particle is
The energy stored in a capacitor is $W$. To double the charge on the plates of the capacitor, the additional work to be done is
Two blocks A and B of masses 2 kg and 4 kg respectively are kept on a rough horizontal surface. If same force of 20 N is applied on each block, then the ratio of the accelerations of the blocks A and B is (Coefficient of kinetic friction between the surface and the blocks is 0.3 and acceleration due to gravity = \(10 \operatorname{ms}^{-2}\))