Question

Three identical iron balls A, B, and C having temperatures of 80℃, 30℃, and 30℃ respectively are connected with metal rods as shown. Identify the correct direction of heat flow among the balls.

• A.
  Ball A → Ball B ← Ball C
• B.
  Ball A ← Ball B → Ball C​
• C.
  Ball B ← Ball A → Ball C
• D.
  Ball A → Ball B →Ball C​

Answer 1

The correct option is C

Ball B ← Ball A → Ball C
Heat always flows from a hot body (body at a higher temperature) to a cold body (body at a lower temperature).
The flow of heat stops when the two bodies attain equal temperatures. Thus, there is no heat flow between the bodies at the same temperature.

Given,
The temperature of ball A = 80℃
The temperature of ball B = 30℃
The temperature of ball C = 30℃
The temperature of ball A is the highest among all the balls. Also, the temperatures of balls B and C are the same.
So, the heat will flow from ball A to ball B and ball C. And there is no heat flow between balls B and C.