(a)[2]
State what the term magnetic field means.
(b)
A particle of charge $+q$ and mass $m$ moves in a vacuum at speed $v$. The particle enters a uniform magnetic field of flux density $B$ at right angles, as shown in Fig. 8.1. It leaves the field after tracing a semi-circular path of diameter $d$.
(b(i))[1]
State the direction in which the magnetic field acts.
(b(ii))[2]
Explain why the speed of the particle does not change in the magnetic field.
(b(iii))[2]
Show that the diameter $d$ of the semi-circular path is given by $d = \frac{2mv}{Bq}$.
(b(iv))[2]
Use the result in (b)(iii) to show that the time $T_F$ spent in the field by the particle does not depend on its speed $v$.