Use the circuit below for questions $17-21.$

$\frac{v_1-110}{15}+\frac{v_1-v_2}{5}$

Question $17$: Determine the Thevenin voltage with respect to terminals $a-b.$

$($A$)55$ V

$($D$)-80$ V

$($B$)50$ V

$($E$)$ None of the above

$($C$)80$ V

Question $18$: Determine the Norton current with respect to terminals a$-$b$.$

$($A$)10$ A

$($D$)-13\mathrm{.}75$ A

$($B$)3\mathrm{.}75$ A

$($E$)$ None of the above

Use the circuit below for questions $17-21$

$($C$)3\mathrm{.}75$ A

Question $19$: Determine the Thevenin resistance with respect to terminals a$-$b$.$

$($A$)5\mathrm{.}71$

$($D$)20$

$($B$)5\mathrm{.}82$

$($E$)$ None of the above

$($C$)4$

Question $20$: Determine the load resistance to be connected across terminals for $a-b$ for maximum power delivery to the load.

$($A$)4$

$($B$)5\mathrm{.}71$

$($D$)5\mathrm{.}82$

$($C$)20$

$($E$)$ None of the above

Question $21$: Determine the maximum power that can be delivered to any RL$.$

$($A$)275$ W $4$

$($D$)100$ W

$($B$)189\mathrm{.}06$ W

$($E$)$ None of the above

$($C$)171\mathrm{.}88$ W

$\frac{1}{4}\frac{v^2}{r^2}$