Institution: SONALI BANK LTD Exam: Sonali Bank Ltd - Sub-Assistant Engineer (Mechanical) - 30.09.2016 ||
Topic: Scientific, Subject: General Science (সাধারণ বিজ্ঞান)

Best Answer Explained in Below-:

In refrigeration systems, the term 'C.O.P.' (Coefficient of Performance) is crucial as it measures the efficiency of the refrigeration cycle. It is defined as the ratio of useful refrigeration effect produced to the work input required for that effect. The concept of 'per ton refrigeration capacity' is commonly used in the industry, where one ton of refrigeration is equivalent to the ability to remove heat at the rate of 3.5 kW.

To relate this to C.O.P., if we consider the performance of a refrigeration system, we find that one ton of refrigeration can effectively remove 3.5 units of heat per hour. Therefore, the total power required to achieve this effect can be represented as heat removed (3.5) divided by the efficiency of the system (C.O.P.). Hence, the relationship can be formulated as:

\[
\text{Per Ton Refrigeration Capacity} = \frac{3.5}{C.O.P.}
\]

This formula shows that as the efficiency (C.O.P.) increases, the amount of power required to achieve one ton of refrigeration decreases, thus validating option D: \( \frac{3.5}{C.O.P.} \) as the correct answer. This inverse relationship highlights the significance of C.O.P. in determining effective refrigeration capacity.