List of top Physics Questions

In an electromagnetic wave:
A metal ring is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet is:
Escape velocity when a body of mass \( m \) is thrown vertically from the surface of the earth is \( v \). What will be the escape velocity of another body of mass 4m thrown vertically?
A particle having a mass 0.5 kg is projected under gravity with a speed of 98 m/s at an angle of \( 60^\circ \). The magnitude of the change in momentum (in N-sec) of the particle after 10 seconds is:
A man holding a rifle (mass of person and rifle together is 100 kg) stands on a smooth surface and fires 10 shots horizontally in 5 sec. Each bullet has a mass 10 g with a muzzle velocity of 800 m/s. The velocity which the rifle man attains after firing 10 shots will be:
A particle covers half of the circle of radius \( r \). Then the displacement and distance of the particle are respectively:
The figure below shows currents in a part of electric circuit. The current \( i \) is:
A mass of 0.5 kg moving with a speed of 1.5 m/s on a horizontal smooth surface, collides with a nearly weightless spring of force constant \( k = 50 \, \text{N/m} \). The maximum compression of the spring would be:
Consider a pair of insulating blocks with thermal resistances \( R_1 \) and \( R_2 \) as shown in the figure. The temperature \( \theta \) at the boundary between the two blocks is:
A rain drop of radius 0.3 mm has a terminal velocity in air is 1 m/s. The viscosity of air is \( 8 \times 10^{-5} \) poise. The viscous force on it is:
A solid sphere is rotating in free space. If the radius of the sphere is increased keeping the mass the same, which one of the following will not be affected?
The Young’s modulus of a perfectly rigid body is:
The equivalent capacitance of the combination of the capacitors is:
The half-life period and the mean life period of a radioactive element are denoted respectively by \( T_h \) and \( T_m \). Then:
An electric dipole is kept in a uniform electric field. It experiences:
The velocity-time graph of a body moving in a straight line is shown in the figure. Find the displacement and distance travelled by the body in 10 seconds.
A person swims in a river aiming to reach exactly on the opposite point on the bank of a river. His speed of swimming is 0.5 m/s at an angle of 120° with the direction of flow of water. The speed of water is:
In a common base mode of a transistor, the collector current is 5.488 mA for an emitter current of 5.60 mA. The value of the base current amplification factor \( \beta \) will be:
The magnetic field at a distance \( r \) from a long wire carrying current is 0.4 tesla. The magnetic field at a distance \( 2r \) is:
A point charge \( q \) is rotated along a circle in the electric field generated by another point charge \( Q \). The work done by the electric field on the rotating charge in one complete revolution is:
Radioactive element decays to form a stable nuclide, then the rate of decay of reactant is shown by:
Which of the following gates will have an output of 1?
If the kinetic energy of a free electron doubles, its de-Broglie wavelength changes by the factor:
The ratio of the energies of the hydrogen atom in its first to second excited states is:
The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then: