In a conventional domestic refrigerator, the evaporator/freezer coil is located at the top. While colder air sinks, the bottom storage section (the crisper/vegetable bin) is purposefully shielded and insulated from direct cold air convection to maintain warmer temperatures ($+8^\circ\text{C}$ to $+10^\circ\text{C}$) to prevent freezing injury to sensitive vegetables and fruits, making it the least cold compartment.

Option analysis:

• Top of refrigerator cabinet: Situated immediately below or adjacent to the evaporator, maintaining very cold temperatures ($+1^\circ\text{C}$ to $+3^\circ\text{C}$).
• Middle of refrigerator cabinet: Moderate intermediate temperature zone ($+4^\circ\text{C}$ to $+5^\circ\text{C}$).
• Bottom of refrigerator cabinet: Correct, crisper drawers at the bottom are the least cold zone ($+8^\circ\text{C}$ to $+10^\circ\text{C}$).
• Tray meant for storing milk: Located directly beneath the chiller/freezer, highly cold.

In a vapour compression refrigeration plant, the liquid receiver is a pressure vessel installed immediately downstream of the condenser. It serves as a surge tank and bulk storage reservoir for excess liquid refrigerant during operational load fluctuations and holds the entire refrigerant charge during pump-down maintenance.

Option analysis:

• Compressor: Compresses low-pressure vapor to high pressure, does not store liquid refrigerant.
• Condenser: Heat exchanger where vapor condenses to liquid.
• Evaporator: Heat exchanger where liquid boils to absorb heat.
• Receiver: Correct, specialized storage tank for holding liquid refrigerant.

One ton of refrigeration (TR) is defined as the rate of heat extraction needed to freeze $1\text{ short ton}$ ($2000\text{ lb}$ or $907.18\text{ kg}$) of pure water at $0^\circ\text{C}$ into ice at $0^\circ\text{C}$ in $24\text{ hours}$:

$$1\text{ TR} = \frac{2000\text{ lb} \times 144\text{ BTU/lb}}{24\text{ hours}} = 12000\text{ BTU/h} = 200\text{ BTU/min}$$

Converting to SI metric units:

$$1\text{ TR} = 210.98\text{ kJ/min} \approx 211\text{ kJ/min} = \frac{210.98}{60}\text{ kJ/s} = 3.5167\text{ kW}$$

Option analysis:

• $1\text{ TR} = 311\text{ kJ/min} = 5.5167\text{ kW}$: Incorrect values.
• $1\text{ TR} = 111\text{ kJ/min} = 4.5167\text{ kW}$: Incorrect values.
• $1\text{ TR} = 411\text{ kJ/min} = 2.5167\text{ kW}$: Incorrect values.
• $1\text{ TR} = 211\text{ kJ/min} = 3.5167\text{ kW}$: Correct standard thermodynamic equivalents.