State and explain Thevenin's theorem. By applying Thevenin's theorem or otherewise, find the current through the resistance $R$ and the voltage across it when connected as shown in Fig. $2\mathrm{.}178.$

$|60\mathrm{.}49$ A$,600\mathrm{.}49$ V$|($Elect$.$ and Mech. Technology, Osmania Univ.$)$

State and explain Thevenin's theorem.

For the circuit shown in Fig. $2\mathrm{.}179,$ determine the current through $R_2$ when its value is $50$ Find the value of $R_L$ for which the power drawn from the source is maximum.

$($Elect$.$ Technology I, Gwalior Univ.$)$