Moving Charges and Magnetism

When a charged particle moves into a magnetic field at a right angle (normally), it starts moving in a circle because the magnetic force keeps turning it.
The time it takes to complete one full circle (the time period T ) is given by:
T=‌

2πm

Bq

Here, m is the mass of the particle, q is its charge, and B is the magnetic field strength.
You can also write it as:
T=‌

2π

B⋅(‌ q m )

This means the time period T is inversely related to the specific charge (‌

q

m

) (charge divided by mass).
So, if the specific charge increases, the time period decreases, and if the specific charge decreases, the time period increases.