Question

Write the special features of Magnetic Lorentz force.

Answer 1

Hint : To answer this question, we have to write the equation for the magnetic component of the Lorentz force. Then observing its dependence on the quantities, we can write its special features.

Complete step by step answer
We know that the Lorentz force is the force experienced by a charged particle when it moves in a region of electromagnetic field. We know that the electromagnetic field consists of the electric and the magnetic fields, so the Lorentz force is equal to the vector sum of the forces due to the electric and the magnetic fields, that is,
 $ \vec F = q\left( {\vec E + \vec V \times \vec B} \right) $
Now, writing the magnetic component of the Lorentz force, we get the magnetic Lorentz force as
 $ {\vec F_M} = q\left( {\vec V \times \vec B} \right) $
Now, as we can see from the above expression that the magnetic Lorentz force is equal to the product of the charge and the cross product of the velocity with the magnetic field. So we can write its special features as
As the cross product of velocity and the magnetic field is involved, this force is perpendicular to the plane of the velocity of the charged particle and the magnetic field. Also, this force is zero if the charge moves parallel or anti parallel to the magnetic field. Also, if the velocity of the charge is equal to zero, then this force is equal to zero. Therefore this force cannot act on a stationary charge.
This force will be maximum when the charge is parallel to the magnetic field present.

Note
The Lorentz force discussed in this question finds its applications in many engineering devices. It occurs in the devices such as cyclotrons, magnetrons, velocity filters etc. Also, it occurs in the electrical devices including electric motors, loudspeakers, electric generators etc.