Question

When a charged particle perform helical motion and when not

Answer 1

In contrast, the magnetic force on a charge particle is orthogonal to the magnetic field vector, and depends on the velocity of the particle. The right hand rule can be used to determine the direction of the force. An electric field may do work on a charged particle, while a magnetic field does no work.

Answer 2

Charged particle perform helical motion when -

Particle experiences this at each point direction of force towards center..so it will move in a circular motion due to centripital force.

Formula for centripital force->mv^2/r.

Now this force will move particle in uniform circular motion.

Magnetic force=centripital force

qvB=mv^2/r

r=mv/qB where r=radius of circular

path

2>when particle move at any angle

0<○<90

It has both component of velocity

vcos○>>will move it forward

vsin○>>will move it into circular

motion.

Due to their combined effect ;formation of helical motion takes place.

For helical motion》

Pitch= distance travelled in one

revolution

=speed×time period

=vcos○×2*pie*m/qB

=2*pie*m/qB ×v cos○

If the above condition is not satidfied by a charged particle then particle will not show helical motion.

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