Question 999: Thermodynamics & KTG

Question

The temperature inside a refrigerator is t2 oC. The amount of heat delivered to the room for each joule of electrical energy consumed ideally will be

Accepted Answer

Temperature inside refrigerator = t
2
ÃÂ°C
Room temperature = t
1
ÃÂ°C
For refrigerator,
$${{{\rm{Heat\,given\,to\,high\,temperature}}\,\left( {{Q_1}} \right)} \over {{\rm{Heat\,taken\,from\,lower \,temperature\, }}\left( {{Q_2}} \right)}} = {{{T_1}} \over {{T_2}}}$$
$${{{Q_1}} \over {{Q_2}}} = {{{t_1} + 273} \over {{t_2} + 273}}$$
$$ \Rightarrow {{{Q_1}} \over {{Q_1} - W}} = {{{t_1} + 273} \over {{t_2} + 273}}$$
$$ \Rightarrow 1 - {W \over {{Q_1}}} = {{{t_2} + 273} \over {{t_1} + 273}}$$
$$ \Rightarrow {W \over {{Q_1}}} = {{{t_1} - {t_2}} \over {{t_1} + 273}}$$
The amount of heat delivered to the room for each joule of electrical energy (W = 1 J)
$${Q_1} = {{{t_1} + 273} \over {{t_1} - {t_2}}}$$

Answer

$${{{t_1}} \over {{t_1} - {t_2}}}$$

Answer

$${{{t_1} + 273} \over {{t_1} - {t_2}}}$$

Answer

$${{{t_2} + 273} \over {{t_1} - {t_2}}}$$

Answer

$${{{t_1} + {t_2}} \over {{t_1} + 273}}$$

Thermodynamics & KTG

The temperature inside a refrigerator is t2 oC. The amount of heat delivered to the room for each joule of electrical energy consumed ideally will be

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