Question

13. A solid sphere, solid cylinder and circular disco
same material and mass are maintained at same
temperature. The body which is cooling at fastest
rate is
(1) Solid sphere
(2) Solid cylinder
(3) Circular disc (4) All same​

Answer 1

Dear Student,

◆ Answer -

(3) Circular disc

● Explanation -

As all the objects are of same material they all have same Stephen's constant.

Appyling Stephen's law, net radiating power is given by -

P = σAT⁴

Here, σ and T are constant here.

P ∝ A

For given object, we can arrange according to surface area.

Circular disc > solid cylinder > solid sphere

As circular disc has maximum area, it will cool with fastest speed.

Thanks dear. Hope this helps you...

Answer 2

circular disc

Explanation:

since,

sphere,cube and circular disc have same mass and same density thus all of them have same volume

now,

Among all of them circular disc has maximum surface area provided they have same volume so,energy is radiated at a faster rate from circular disc and thus circular disc cools rapidly