C is matched with 1: Positrons, the antimatter counterparts of electrons, possess fractional spin, matching this characteristic. D is matched with 4: Photons are elementary particles of light with an integral spin of 1, classifying them as bosons. Direction: The following item consists of two statements. One labeled as the ‘Assertion (A)’ and the other as “Reason (R). You have to answer this item using the code given below: 307. Assertion (A): Large cold storage plants use ammonia as refrigerant while domestic refrigerators use chlorofluoro- carbons. Reason (R): Ammonia can be liquefied at ambient temperature and low pressure.

Question

YESPYQ · Accepted Answer

Correct answer: A is true but R is false. Assertion (A) is true: Large cold storage plants often use ammonia as a refrigerant because it has high efficiency in transferring heat. Ammonia is widely used in industrial refrigeration due to its thermodynamic properties and relatively low cost. Domestic refrigerators, on the other hand, typically use chlorofluorocarbons (CFCs) or their replacements, like HFCs, due to their non-toxic and non-flammable nature. Reason (R) is false: Ammonia cannot be liquefied at ambient temperature and low pressure. It requires a higher pressure or lower temperature to be liquefied. Ammonia is typically stored and transported as a liquid under pressure or at low temperatures. Therefore, while the assertion is correct, the reason is false. 308

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