Question

A freezer in the refrigerator is fitted at the top:
A. To keep it away from the hot compressor which is near the bottom.
B. Because of convenience
C. So that it can cool the whole interior by setting up convection currents.
D. Without any specific cause.

Answer 1

Hint:The aim of the refrigerator is to keep the things inside it cool, so it should make use of the freezer which has the lowest temperature compared to the other sections of the fridge to maintain the coolness of the fridge.

Complete step-by-step answer:
Earlier days the fridges were a single entity with a freezer and the other compartments. The freezer which is situated at the top had the lowest temperature compared to other components. So the temperature at the bottom part of the fridge will be really high as compared to the temperature above. So the air at the bottom will be hotter as a result less dense than the air above which is cooler. This density difference of air leads to the process of convection in which the less dense air will rise upwards while the denser will come down. So the hotter air current from the bottom will rise up to the freezer part and the hot air current gets cooled down due to the freezer. The cold air current which was present at the top will go down, this process will eventually decrease the temperature of the whole fridge. So a particular temperature can be maintained in the fridge.
So the answer to our question is option (C)- So that it can cool the whole interior by setting up convection currents.

Note: New refrigerators have separate freezer and this freezer can be placed at the bottom also.Modern fridges use a fan blowing over the cooling coils which allow cold air to be ducted into two or more separate airtight compartments. A balancing damper controlled by a knob allows you to set how much cold air each compartment receives.