16Practical applications of electromagnetic fields

Qualitative (Concept Test)

(1) How does the speed of the particles being accelerated by a cyclotron change; (i) inside a dee and (ii) moving from one dee to the other?

(2) What keeps the particles moving in a circular path?

(3) What two factors limit the maximum speed that the particles can attain in a cyclotron?

(4) What are the limitations of a cyclotron and how does the synchrotron overcome these limitations?

(5) Why do charged particles moving in a circle lose kinetic energy?

(6) How is the energy of charged particles moving inside the circular tunnel of a synchrotron maintained?

Quantitative (Calculation Test)

1. (a) Calculate the energy given to a proton when it moves between 2 dees that have a potential of 1500V across them. The charge on a proton is 1.6 × 10^-19C.

                                                                                                                                                               [2]

(b) What would be the increase in speed of the proton of mass 1.7 ×10^-27kg?

                                                                                                                                                                [3]

2. (a) Calculate the radius of the circular path followed by an electron travelling at a speed of 2.0 × 10⁷ m/s when it is in a magnetic field of 0.10T, perpendicular to it motion. The charge on an electron is

1.6 × 10^-19C and the mass of an electron is 9.11 × 10^-31kg.

                                                                                                                                                                [2]

(b) How long would it take this electron to travel one semi circle?

                                                                                                                                                             [3]