Question

When an electron moves in a transverse magnetic field its path becomes
A.)Circular
B.)Straight line
C.)Parallel
D.)Parabolic

Answer 1

Hint: To find the answer to this question first fin the mathematical expression for a charge particle moving in a uniform magnetic field. Then with the help of the cross product of velocity and magnetic field we can find the direction of force and hence, finally will get the path of the particle.

Complete step by step answer:
Transverse magnetic field can be defined as a mode of electromagnetic wave propagation where the magnetic field is perpendicular to the direction of propagation of the wave.
Now, if a charge particle of charge q is moving in a transverse magnetic field B with velocity v, then magnetic force on the charge particle is given by the Lorentz force as,

$\vec{F}=q\vec{v}\times \vec{B}$

So, the force on the charge particle is given by the cross product of the velocity and magnetic field of the charge particle.

So, we can say that the direction of the magnetic force on the charge particle is perpendicular to both the direction of velocity and the direction of the magnetic field.
This magnetic force acts as the centripetal force on the charged particle. So, the charged particle will move in a curved path in the magnetic field. The particle will move in the curved path and will form a circle.

So, when the electron moves in the transverse magnetic field its path becomes circular.
The correct option is (A)

Note: Lorentz force is the combination of electric and magnetic force on a point charge moving in an electromagnetic field. The force is given as,
$F=q\left( E+v\times B \right)$F
Where the first part gives the electric force on the point charge and the second part gives the magnetic force on the point charge.