Question

A cyclotron is accelerating proton, where the applied magnetic field is 2T and the potential gap is 100 keV. To acquire a kinetic energy of 20 MeV, the number of turns, the proton has to move between the dees is-

• A. 200
• B. 300
• C. 150
• D. 100

Answer 1

Answer: (D)

100

Answer 2

Energy gained in one movement across the gap = 100 KeV The energy gained in one turn = 200 KeV

N = $\frac { 20 \times 10 ^ { 6 } } { 200 \times 10 ^ { 3 } }$ = 100