Question
Physics Question on Moving charges and magnetism
A cyclotron is operated at an oscillator frequency of 12MHz and has a dee radius R=50cm . What is the magnitude of the magnetic field needed for a proton to be accelerated in the cyclotron ?
A
0.72T
B
0.65T
C
0.39T
D
0.12T
Answer
0.72T
Explanation
Solution
Given, f=12MHz=12×10−6Hz
R=50cm=520×10−2m
B=q2πmf
=(1.6×10−19)(12×106)×2×π×(1.67×10−27)
=0.788≈0.72T