Q. A hollow sphere of radius R, a hollow cube of side R and a thin circular plate of radius R, made up of the same material, are all heated to 20°C above room temperature. When left to cool in the room, which of them will reach the room temperature first?
Answer: Sphere
Notes: The loss of heat is directly proportional to the surface area, hence loss of heat will be earlier in case of sphere because it has the maximum surface area.

This question is part of 40000+ General Studies MCQ Series Course on GKToday Android app. Question Number: 15 in General Studies Mock Test - 77 in above course in App.