$6-171$ An air$-$conditioning system operating on the reversed Carnot cycle is required to remove heat from the house at a rate

of $32k\frac{J}{s}$ to keep its temperature constant at $20C.$ If the temperature of the outdoors is $35C,$ the power required to operate this air$-$conditioning system is

$($a$)0\mathrm{.}58$ kW

$($b$)3\mathrm{.}20$ kW

$($c$)1\mathrm{.}56$ kW

$($d$)2\mathrm{.}26$ kW

$($e$)1\mathrm{.}64$ kW

$6-172$ A refrigerator is removing heat from a cold medium at $3C$ at a rate of $5400k\frac{J}{h}$ and rejecting the waste heat to a medium at $30C.$ If the coefficient of performance of the refrigerator is $2,$ the power consumed by the refrigerator is

$($a$)0\mathrm{.}5$ kW

$($b$)0\mathrm{.}75$ kW

$($c$)1\mathrm{.}0$ kW

$($d$)1\mathrm{.}5$ kW

$($e$)3\mathrm{.}0$ kW

$6-173$ Two Carnot heat engines are operating in series such that the heat sink of the first engine serves as the heat source of the second one. If the source temperature of the first engine is $1300$ K and the sink temperature of the second engine is $300$ K and the thermal efficiencies of both engines are the same, the temperature of the intermediate reservoir is

$($a$)625$ K

$($b$)800$ K

$($c$)860$ K

$($d$)453$ K

$($e$)758$ K

$6-174$ A typical new household refrigerator consumes about $680$ kWh of electricity per year and has a coefficient of performance of $1\mathrm{.}4.$ The amount of heat removed by this refrigerator from the refrigerated space per year is

$($a$)952M\frac{J}{y}r$

$($b$)1749M\frac{J}{y}r$

$($c$)2448M\frac{J}{y}r$

$($d$)3427M\frac{J}{y}r$

$($e$)4048M\frac{J}{y}r$