Question

A charged particle is accelerated in a cyclotron. Which of the following statements is correct regarding the forces acting on it?

• A. The magnetic force provides the centripetal force.
• B. The electric force provides the centripetal force.
• C. Both electric and magnetic forces provide the centripetal force.
• D. Neither electric nor magnetic force provides the centripetal force.

Answer 1

Answer: (A)

The magnetic force provides the centripetal force.

Answer 2

The magnetic field is perpendicular to the velocity of the charged particle, causing it to move in a circular path. This magnetic Lorentz force ($F_B = qvB$) acts as the centripetal force ($F_c = \frac{mv^2}{r}$) required for circular motion. The electric field accelerates the particle between the dees, increasing its speed, but it does not provide the centripetal force for the circular path within the dees.