Question

A charged particle moving with constant velocity passes through a region of space without any change in its velocity. If E and B represent electric and magnetic fields in that region respectively, what is the E and B in this space ?
A) E=0 and B=0
B) E=0 and B $\ne$0
C) E $\ne$0 and B $\ne$0
D) E $\ne$0 and B $\ne$0

Answer 1

We know that when a charged particle accelerates means it moves faster or slower, it produces both an electric field and a magnetic field. There is a very simple thing we have to know, if the particle produces an electric field because the particle is charged and if it produces a magnetic field because the particle is moving.

Complete solution:
We know that any moving charged particle will both have the electric and magnetic field. Basically we can say when a charged particle moving with constant velocity passes through a region of space without any change in its velocity, its both magnetic and electric field is not equal to zero, meaning we can write E $\ne$0 and B $\ne$0.

Hence, the correct option is D.

Additional information:
In case we placed a charged particle in the electric field the electric force can be defined as ${F_e} = qE$ where, q is the charge of the particle, E is the electric field.
We know that, when a charged particle is placed in an electric field then, there is electric force acting on it in the direction of the field on positive charge.
And when a charge particle moving in a magnetic field then a magnetic force acts on the charge particle the direction of magnetic force can be found by Fleming`s left hand rule.

Note:
Here we talk about force also, if we consider positive particles lets say proton. When proton moving in a magnetic field then magnetic force can be defined as ${F_m} = qvB\sin \theta$
Where,
q is the charge of particle
v is the velocity of the charge
B is the magnetic field.
$\theta$ is the angle between electric field and magnetic field.