Concept:In a cyclotron, the magnetic force acts as the centripetal force and decides how the radius, velocity, and angular velocity of the charged particle are related.
Explanation:Consider a charged particle of mass
m and charge
q moving with speed
v in a magnetic field
B.
The magnetic force provides the required centripetal force:
qvB=rmv2Cancelling one factor of
v from both sides, we get:
qB=rmvRearranging this expression gives the linear velocity:
v=mqBrFrom this relation, as the radius
r increases, the linear velocity
V also increases.
Now, the angular velocity is defined as:
ω=rvSubstituting the expression for
v into this definition:
ω=mqBThus,
ω is independent of the radius and remains constant, provided the particle remains non-relativistic.
Therefore, when the radius of the circular path increases, the linear velocity increases while the angular velocity stays the same.
Answer:Option B:
V increases,
ω remains constant.