Question

In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to other. A charged particle is released from rest in this region. The path of the particle will be a:

• A. circle
• B. helix
• C. straight line
• D. ellipse

Answer 1

The correct option is C straight line

Given :In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to other. A charged particle is released from rest in this region.

Solution :

Particle will experience electric force $F_E=qE$ in the direction of electric field.

Formula for magnetic field $F_B=q(\overrightarrow{V}\times \overrightarrow{B})$

And velocity vector and magnetic field are parellal as electric field and magnetic field are parellal. So particle will experience magnetic force $F_B=0$.Since cross product of parellal vectors is 0.

Hence particle will travel in straight path.

The Correct Opt : C