Correct Answer - Option 2 : As low as possible (3 to 11°)
Explanation:
The temperature difference between the evaporating refrigerant and the medium being cooled determines the cooling rate of the chamber.
More the difference more will be the cooling rate.
If this difference is zero, there will be no heat transfer from the chamber, which is very much required since,
- heat enters from the surrounding due to the limitation of real-life insulations.
- there is no direct contact between the refrigerant and the stuff we keep in the refrigerating chamber.
Again if the difference is very high
- Glass crockery might be shattered when kept due to uneven cooling.
- Power requirement will increase.
So we generally keep this difference somewhere around 3 to 11°C for effective cooling.
