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=‌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=‌This means the time period
T is inversely related to the specific charge
(‌) (charge divided by mass).
So, if the specific charge increases, the time period decreases, and if the specific charge decreases, the time period increases.