& x20; Which of the following is used as a cooling agent in refrigerator? - ESIC Nursing Officer 2016 (Shift -2)

ESIC Nursing Officer 2016 (Shift -2)

General Knowledge

Easy

Appeared in: ESIC Nursing Officer 2016 (Shift -2)

Explanation

Liquid ammonia is an effective refrigerant due to its high latent heat of vaporization, meaning it absorbs a significant amount of heat when it changes from a liquid to a gas.
Its boiling point of -33.3°C is suitable for maintaining the temperatures required in standard and industrial refrigeration systems.
It is commonly used in large-scale cooling applications like ice plants and cold storage facilities.

Option A: Liquid hydrogen is extremely flammable and is primarily used as a high-energy rocket fuel, not as a refrigerant in consumer appliances.
Option C: Liquid nitrogen is a cryogenic fluid with a boiling point of -196°C, which is excessively cold for standard refrigeration. It is used for flash-freezing and preserving biological materials.
Option D: Liquid helium has an extremely low boiling point (-269°C) and is used for specialized applications requiring near-absolute zero temperatures, such as cooling the superconducting magnets in MRI machines.

Visual 1: Diagram: Vapor Compression Refrigeration Cycle - To illustrate how a refrigerant like ammonia absorbs and releases heat to create a cooling effect.
Visual 2: Infographic: Comparison of Refrigerants - Showing the boiling points and common applications of ammonia, nitrogen, helium, and hydrogen.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Refrigerants and Cooling Agents as background academic context rather than a clinical decision trigger.
Proper refrigeration is critical in healthcare for storing vaccines, medications (like insulin), and blood products to maintain their efficacy and safety. The principles of refrigeration are fundamental to the 'cold chain' system (SRC_2, SRC_3).
While ammonia is used in large industrial units, other refrigerants are used in smaller medical-grade refrigerators found in clinics and hospitals.
Cryogens like liquid nitrogen have direct medical applications in dermatology (cryosurgery for warts) and reproductive medicine (cryopreservation of gametes and embryos).

How to Approach the Question

Identify the key terms in the question: 'cooling agent' and 'refrigerator'.
This is a factual recall question from general science/chemistry.
Evaluate each option based on its known primary use.
Recall that ammonia is a common, traditional refrigerant, especially in industrial settings.
Eliminate the other options by identifying their specific, non-refrigeration applications: hydrogen (fuel), nitrogen (cryogenics), and helium (supercooling for MRIs).
Select the option that best fits the context of standard refrigeration.

Concept Tested & Keywords

QscFetJ85fCdwghHYdN_WX