Question

Question 23 Which of the following is NOT something a charge can experience in a static magnetic field? Change in direction Force b. Change in kinetic energy ос. d. Change in momentum Acceleration e.

Answer 1

Correct option is : (c) Change in kinetic energy.

Reason :

A charge q, moving with velocity v in a magnetic field B experiences a magnetic force
F
= q
ין
x
B
.

So, there is a non - zero force applied on the particle, thus, option (b) is incorrect.

Since the force is a cross product of the velocity vector and the magnetic field vector, the particle also may change its direction too, thus, option (a) is also incorrect.

Since direction of motion is changinf, momentum also changes. So, option (d) is incorrect too.

There if the angle between the velocity vector and the magnetic field vector is non - zero, then the particle rotates in a circular path, and thus it rotates under a non - zero centripetal acceleration. This makes option (e) to be incorrect also.

Finally, since there is no change in the magnitude of the particle's velocity, there is no change in its kinetic energy too. So, option (c) is the correct one.