(a(i))[1]
Explain why a force acts on side AB.
(a(ii))[2]
Determine the direction of the current in AB and state the basis used to deduce it.
(b)[2]
Since both side AB and side CD of the coil are $2.5\,\text{cm}$ from the axis, determine the total moment acting on the coil.
(c(i))[1]
Fig. 7.1 shows the coil as part of a direct current (d.c.) motor. State the name of the component that links the coil of a d.c. motor to the electricity supply.
(c(ii))[1]
State one modification to the arrangement in Fig. 7.1 that would give coil ABCD a larger turning effect.