An ideal refrigerator has a freezer at a temperature of -13 oC . The coefficient of performance of the engine is 5 . The temperature of the air at which heat is rejected will be

Question

An ideal refrigerator has a freezer at a temperature of -13 oC . The coefficient of performance of the engine is 5 . The temperature of the air at which heat is rejected will be (A) 325 oC (B) 325 K (C) 39 oC (D) 320oC

Tardigrade Admin · Accepted Answer

Coefficient of performance α =(TC/TH - TC) TC=273-13=260K 5=(260/TH - 260) TH=312K ∴ TH=312-273=39oC

Q. An ideal refrigerator has a freezer at a temperature of $- 13^{o} C$ . The coefficient of performance of the engine is $5$ . The temperature of the air at which heat is rejected will be

$325^{o} C$

$325 K$

$3 9^{o} C$

$32 0^{o} C$

Coefficient of performance $α = \frac{T _{C}}{T _{H} - T _{C}}$
$T_{C} = 273 - 13 = 260 K$
$5 = \frac{260}{T _{H} - 260}$
$T_{H} = 312 K$
$∴ T_{H} = 312 - 273 = 3 9^{o} C$

Q. An ideal refrigerator has a freezer at a temperature of −13oC . The coefficient of performance of the engine is 5 . The temperature of the air at which heat is rejected will be

325oC

325K

39oC

320oC