1. If a charged particle moves through a magnetic field perpendicular to it ?

momentum is constant but energy changes.

energy is constant but momentum changes.

momentum as well as energy are constant.

both momentum and energy of particle change.

Answer: energy is constant but momentum changes.


Since the direction of velocity of a particle varies so momentum changes but direction of magnetic force is always perpendicular to direction of charged particle. So no work is done, i.e. energy remains the same.

2. A strong magnetic field is applied on a stationary electron. Then the electron ?

moves opposite to the direction of the field.

moves perpendicular to the direction of the field.

remained stationary.

moves in the direction of the field.

Answer: remained stationary.


3. The nature of parallel and anti-parallel currents are ?

parallel currents attract and antiparallel currents repel.

both currents repel.

parallel currents repel and antiparallel currents attract.

both currents attract.

Answer: parallel currents attract and antiparallel currents repel.


4. Energy in a current carrying coil is stored in the form of ?


electric field

magnetic field

dielectric strength

Answer: magnetic field


5. To make the field radial in a moving coil galvanometer ?

coil is wounded on aluminium frame

poles are cylindrically cut

magnet is taken in the form of horse-shoe

the number of turns in the coil is increased

Answer: poles are cylindrically cut


6. The AC voltage across a resistance can be measured using a ?

moving magnet galvanometer

potential coil galvanometer

hot wire voltmeter

moving coil galvanometer

Answer: moving coil galvanometer


7. In cyclotron the gyro radius is ?

inversely proportional to energy

proportional to momentum

proportional to energy

inversely proportional to momentum

Answer: proportional to momentum


8. If a current is passed through a spring then the spring will ?

remains same



None of these

Answer: compress


9. A current carrying loop is placed in a uniform magnetic field. The torque acting on it does not depend upon ?

value of current

magnetic field

area of loop

None of these

Answer: None of these


10. A charged particle moving in a uniform magnetic field and losses 4% of its kinetic energy. The radius of curvature of its path changes by ?





Answer: 10%