Question 950: Thermodynamics & KTG

Question

The coefficient of performance of a refrigerator is 5. If the temperature inside freezer is $$-$$20
o
C, the temperature of the surroundings to which it rejects heat is

Accepted Answer

Coefficient of performance,
$$Cop = {{{T_2}} \over {{T_1} - {T_2}}}$$
$$5 = {{273 - 20} \over {{T_1} - \left( {273 - 20} ight)}} = {{253} \over {{T_1} - 253}}$$
5T
1
Ã¢ÂÂ (5 ÃÂ 253) = 253
5T
1
= 253 + (5 ÃÂ 253) = 1518
$$ 	herefore $$ $${T_1} = {{1518} \over 5} = 303.6$$
$$ \Rightarrow $$ T
1
= 303.6 Ã¢ÂÂ 273 = 30.6 $$ \cong $$ 31ÃÂ°C

Answer

11
o
C

Answer

21
o
C

Answer

31
o
C

Answer

41
o
C

Thermodynamics & KTG

The coefficient of performance of a refrigerator is 5. If the temperature inside freezer is $-$20 o C, the temperature of the surroundings to which it rejects heat is

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