(a(i))[1]
State why the primary and secondary coils are wound on an iron core.
(a(ii))[3]
Suggest why thermal energy is produced in the core when the transformer is operating.
(b(i))[2]
Explain, using direct current as a reference, what is meant by the root-mean-square value of an alternating current.
(b(ii))[2]
Show that, for an ideal transformer, $\frac{V_S}{V_P} = \frac{I_P}{I_S}$.