A certain coal$-$fired power plant has a rated power capacity of P $=650$ MW$.$ The output of this plant is W $=0\mathrm{.}27$QH$,$ where QH is the energy input as heat from the hot reservoir.

$-$ Part $($a$)$

Write an equation for the efficiency of a heat engine in terms of QH and the heat QC exhausted to a low temperature reservoir.

$=1-$QC$/$QH$$Correct$!$

$-$ Part $($b$)$

Which would increase the efficiency more, doubling QH or reducing QC by half?

Doubling Qh and reducing Qc by half will have the same effect in increasing the efficiency.$$Correct$!$

$-$ Part $($c$)$

Calculate the maximum thermal efficiency of the power plant.

$=0\mathrm{.}27000\mathrm{.}2700$Correct$!$

$$ Part $($d$)$

Calculate the absolute value of the exhausted heat $($QC$)$ each second in MJ for the power plant.