Describe the motion of a charged particle in a cyclotron if the frequency of the radio frequency (rf) field was doubled.

Hint: The motion of the charged particle depends on the frequency of the electric field.
Step 1: Here, the condition of magnetic resonance is violated. When the frequency of the radio frequency (rf) field is doubled, the time period of the radio frequency (rf) field will be halved. Therefore, the duration in which particle completes half revolution inside the dees, radiofrequency completes one cycle.
Step 2: Hence, the particle will accelerate and decelerate alternatively. So, the radius of the path in the dees will remain the same.