Question

Which of the following are true about magnetic fields? a) more than one of these b) they always cause a moving charge to accelerate c) They are stronger than electric fields d) They will cause a static charge to accelerate e) they can be associated with an isolated north pole or isolated south pole f) they sometimes cause a moving charge to accelerate

Answer 1

b) Force of magnetic field on a moving charge = q(vxB )
For v and B in same direction, force is zero. Hence magnetic field accelerates moving charge, only if angle between v and B is other than zero or pi.
Statement b is wrong and f is true.

c) False. Generally force of electric field is stronger than that of magnetic field.

d) Magnetic field applies force only on moving charge, q(vxB ). Hence d is wrong

e) false , as isolated north and south poles don't exist.