$($b$)$ A $33k\frac{V}{11}kV,3-$phase transformer has the protecting current transformer on the high voltage side and low voltage side with a ratio of $\frac{300}{1}$ and $800/1$ respectively. The line current of the transformer on the primary side is $150$ A and the line current on the secondary side is $450$ A $.$

Draw the scheme of differential relay and calculate:

$($i$)$ Current in the pilot wires

$($ii$)$ Current through the relays

$($ii$)$ CT ratio mismatch