Question

.......... of refrigerator is the ratio of heat extracted to the work done to produce the refrigeration effect

• A. Power
• B. Energy
• C. COP
• D. Efficiency

Hint:

Refrigerators don't "create cold"; they "move heat." Because they move existing energy, the "Coefficient" is often between 2 and 4, whereas an engine's "Efficiency" is usually around 0.3.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks for the thermodynamic parameter used to measure the performance efficiency of a refrigeration system.
Key Formula or Approach: \[ COP = \frac{\text{Desired Effect}}{\text{Energy Input}} = \frac{Q_L}{W} \] Where \(Q_L\) is the heat removed from the cold space and \(W\) is the electrical work input.

Step 2: Detailed Explanation:

• In heat engines, we use the term "Efficiency," which is always less than 1 (Work output Heat input).

• For refrigeration cycles (refrigerators, freezers, ACs), we use the Coefficient of Performance (COP).

• The "desired effect" in a refrigerator is to remove heat (\(Q_L\)) from the food storage compartment to keep it cold.

• To do this, we must supply mechanical work (\(W\)) through a compressor.

• Unlike thermal efficiency, the COP of a refrigerator can be (and usually is) greater than 1. This means the amount of heat energy moved is greater than the work energy consumed.

• A higher COP indicates a more energy-efficient refrigeration system.

Step 3: Final Answer: The ratio described is the Coefficient of Performance (COP).