Question

Pick up the correct statements :

• A. The changing (with time) magnetic field need not be in existence at the location of induced electric field.
• B. A uniform magnetic field increasing at constant rate, induces an electric field which is constant and non conservative.
• C. Non zero force exerted by uniform and constant magnetic field on a moving charged particle does no work but always changes momentum of the particle.
• D. All the above statements are wrong.

Answer 1

Answer: (A), (B), (C)

The correct options are
A The changing (with time) magnetic field need not be in existence at the location of induced electric field.
B A uniform magnetic field increasing at constant rate, induces an electric field which is constant and non conservative.
C Non zero force exerted by uniform and constant magnetic field on a moving charged particle does no work but always changes momentum of the particle.

(1) If magnetic field inside long solenoid changes with time, electric field is also induced outside the solenoid. Hence true.

(2)Since induced electric field is directly proportional to rate of change of magnetic field, the induced electric field in this case must be constant. Hence true.

(3) The force is perpendicular to the direction of motion thus it does no work. The force does change the momentum direction wise or otherwise.