Consider the following circuit.

$($a$).$ Find the Thevenin equivalent of the circuit, as seen by terminals $$ A and B$.$ This involves calculating the appropriate voltage voc and resistance Req. The voltage should be measured from A to B $(2$ marks$).($b$).$ Find the Norton equivalent of the circuit, as seen by terminals A and B$.$ This involves calculating the appropriate current isc and resistance Req. The current should be measured as flowing from A to B $(2$ marks$).$ i$.$e$.$ i N $=$ isc and R N $=$ Req $.$