List of top Physics Questions

The condition \( dw = dq \) holds good in the following process:
The maximum height attained by the projectile is increased by 10% by keeping the angle of projection constant. What is the percentage increase in the time of flight?

In the given circuit, if the potential at point B is 24 V, the potential at point A is: 

Pure silicon at 300K has equal electron and hole concentration of \( 1.5 \times 10^{16} \) m\(^{-3}\). If the hole concentration increases to \( 3 \times 10^{22} \) m\(^{-3}\), then the electron concentration in the silicon is:
When a wave enters into a rarer medium from a denser medium, the property of the wave which remains constant is:
The surface areas of two nuclei are in the ratio \( 9:25 \). The mass numbers of the nuclei are in the ratio:
A proton and an alpha particle moving with energies in the ratio \( 1:4 \) enter a uniform magnetic field of 37 T at right angles to the direction of the field. The ratio of the magnetic forces acting on the proton and the alpha particle is:
The efficiency of a Carnot engine is found to increase from 25% to 40% on increasing the temperature (\(T_1\)) of the source alone through 100 K. The temperature (\(T_2\)) of the sink is given by:
A charged particle moving along a straight-line path enters a uniform magnetic field of \( 4 \) mT at right angles to the direction of the magnetic field. If the specific charge of the charged particle is \( 8 \times 10^7 \) C/kg, the angular velocity of the particle in the magnetic field is:
The focal length of the objective lens of a telescope is 30 cm and that of its eye lens is 3 cm. It is focused on a scale at a distance 2 m from it. The distance of the objective lens from the eye lens to see the clear image is:
In a common emitter amplifier, a.c. current gain is 40 and input resistance is 1 kΩ. The load resistance is given as 10 kΩ. Then the voltage gain is:
A solid sphere of mass 50 kg and radius 20 cm is rotating about its diameter with an angular velocity of 420 rpm. The angular momentum of the sphere is:
The ground state energy of hydrogen atom is -13.6 eV. The potential energy of the electron in this state is:

Heat energy absorbed by a system going through the cyclic process shown in the figure is: 

The masses of a solid cylinder and a hollow cylinder are 3.2 kg and 1.6 kg respectively. Both the solid cylinder and hollow cylinder start from rest from the top of an inclined plane and roll down without slipping. If both the cylinders have equal radius and the acceleration of the solid cylinder is \( 4 { ms}^{-2} \), the acceleration of the hollow cylinder is:

Derive an expression for maximum speed of a vehicle moving along a horizontal circular track.

When an A.C. source is connected to a inductive circuit,
A body of mass 1.5 kg is moving towards south with a uniform velocity of \( 8 { ms}^{-1} \). A force of \( 6 \) N is applied to the body towards east. The displacement of the body 3 seconds after the application of the force is:
A car travelling at a speed of \(54 \, \text{kmph}\) towards a wall sounds a horn of frequency \(400 \, \text{Hz}\). The difference in the frequencies of two sounds, one received directly from the car and the other reflected from the wall, noticed by a person standing between the car and the wall is: (Speed of sound in air is \(335 \, \text{m/s}\))

When a monochromatic light is incident on a surface separating two media, both the reflected and refracted lights have the same: 

When a convex lens is immersed in two different liquids of refractive indices 1.25 and 1.5, the ratio of the focal lengths of the lens is 5:16. The refractive index of the material of the lens is:

The tension applied to a metal wire of one metre length produces an elastic strain of 1%. The density of the metal is \( 8000 \, kg/m^3 \) and Young's modulus of the metal is \( 2 \times 10^{11} \, Nm^{-2} \). The fundamental frequency of the transverse waves in the metal wire is: 

Two light waves of intensities \( I \) and \( 2I \) superimpose on each other. If the path difference between the light waves reaching a point is 12.5% of the wavelength of the light, then the resultant intensity at the point is (Both the light waves have the same wavelength)
When unpolarized light incident from air on another medium at an angle of 60°, the reflected light is completely polarized. The refractive index of the medium is:

Two closed pipes when sounded simultaneously in their fundamental modes produce 6 beats per second. If the length of the shorter pipe is 150 cm, then the length of the longer pipe is: \[ \text{(Speed of sound in air = 336 ms}^{-1}) \]