Question

A refrigerator is designed to release 750 calories of heat per second. If the range of its operation is 5 degree Celsius to 25 degree Celsius, then its power is: Ops: A. 226 W B. 250 W C. 300 W D. 330 W​

Answer 1

Answer:

226W

Explanation:

Q =750cal=750 x 4.2=3150J        (1cal=4.2J)

$\beta$ =Q2/W = T2/T1-T2

Q2 =heat released by refrigerator = 3150J

W =work done by refrigerator

T1 = temperature of source in kelvin=25+273=298K

T2 =temperature of sink in kelvin=5+273=278K

Now lets substitute the values into the formula,

3150J/W=278K/298K-278K=278K/20K

3150J X 20K/278K=W

W=226J

Power(P)=work/time

P=226/1=226W

The power is 226W.

The option A is correct.