The figure below shows a simple laminated iron-cored transformer consisting of a primary coil of 25,000 turns and a secondary coil of 625 turns.
The output potential difference (p.d.) 
is applied to a load resistor of resistance 
. The input p.d. 
is a sinusoidal alternating voltage of peak value 
and period 
.
Calculate the maximum value of .
Calculate the root-mean-square (r.m.s.) current in the load resistor.
.
.
