ANS:B - 5

To calculate the coefficient of performance (COP) of a Carnot cycle refrigerator operating between two temperature reservoirs, we use the formula: COP=​TL/TH​−TL​​ Where:

• TH​ is the temperature of the hot reservoir (in Kelvin).
• TL​ is the temperature of the cold reservoir (in Kelvin).

Given that the Carnot cycle refrigerator operates between -23°C and +27°C, we need to convert these temperatures to Kelvin:

• TH​=Thot​=27°C+273.15=300.15K
• TL​=Tcold​=−23°C+273.15=250.15K

Now, we can substitute these values into the formula: COP=250.15/300.15−250.15 =250.15/50​=5 Therefore, the coefficient of performance (COP) of the Carnot cycle refrigerator operating between -23°C and +27°C is 5.