A hollow sphere and a solid sphere of the same material and equal radii are heated to the same temperature. In this case, (A) The cooling rate will be the same for the two spheres and hence the two spheres will have equal temperatures at any instant (B) Both the spheres will emit equal amount of radiation per unit time in the beginning (C) Both will absorb equal amount of radiation from the surrounding in the beginning (D) Both (B) & (C)

A hollow sphere and a solid sphere of the same material and equal radii

are heated to the same temperature. In this case,

(A) The cooling rate will be the same for the two spheres and hence the two

spheres will have equal temperatures at any instant

(B) Both the spheres will emit equal amount of radiation per unit time in the

beginning

(C) Both will absorb equal amount of radiation from the surrounding in the

beginning

(D) Both (B) & (C)

by

1 Answer

Answer :

(D) Both (B) & (C)

by

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Three solid objects of the same material and of equal mass-a sphere, a cylinder (length = diameter) and a cube are at 500°C initially. These are dropped in a quenching bath containing a large volume of cooling oil each attaining the bath temperature eventually. The time required for 90% change in temperature is the smallest for (A) Cube (B) Cylinder (C) Sphere (D) Equal for all the three

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Last Answer : This answer was deleted by our moderators...

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