Assertion (A): Two metallic spheres of same size, one of copper and the other of aluminium, heated to the same temperature, will cool at the same rate when they are suspended in the same enclosure.
Reason (R): The rate of cooling of a body depends only on the excess of temperature of the body over the surroundings.
(1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
(2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(3) (A) is true but (R) is false
(4) Both (A) and (R) are false
Solution:
Assertion (A) is false because cooling rate depends on material properties like specific heat capacity and emissivity, which differ for copper and aluminium. Reason (R) is false.
Newton's Law of Cooling shows rate depends on surface area and emissivity, not just temperature difference.
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