The vapour compression refrigerator employs the following cycle

Answer: Option D

The vapor compression refrigeration cycle employed by a typical refrigerator is a Reversed Rankine cycle. The Rankine cycle is commonly used in thermodynamic systems, especially in power plants, to convert heat energy into mechanical work. However, in a refrigeration system, the Rankine cycle is reversed to create a cooling effect.

The basic components of a vapor compression refrigeration system include a compressor, a condenser, an expansion valve, and an evaporator. Here's how the Reversed Rankine cycle works in a refrigerator:

1. Compression: The low-pressure, low-temperature vapor from the evaporator is compressed by the compressor, increasing its pressure and temperature.
2. Condensation: The high-pressure, high-temperature vapor is then condensed to a liquid in the condenser, releasing heat to the surroundings.
3. Expansion: The high-pressure liquid refrigerant passes through an expansion valve, where its pressure and temperature drop significantly, causing it to partially vaporize.
4. Evaporation: The low-pressure, low-temperature vapor-liquid mixture enters the evaporator, where it absorbs heat from the refrigerated space, cooling it down.

Option A: The Rankine cycle is a thermodynamic cycle used in power plants, not refrigeration systems.
Option B: The Carnot cycle is a theoretical thermodynamic cycle that represents the maximum possible efficiency of a heat engine or refrigerator, but it is not typically used in practical refrigeration systems.
Option D: The Reversed Carnot cycle is a conceptually similar cycle to the Reversed Rankine cycle, but the Rankine cycle is more commonly associated with vapor compression refrigeration.

Therefore, the correct answer is Option C: Reversed Rankine, as it represents the cycle employed by a vapor compression refrigerator to provide cooling.