Question

A copper cylinder of mass 1 kg is heated elecrically by a 15 W heater in a room at ${20}^{\circ }C.$ Temperature of the cylinder increases uniformly to ${30}^{\circ }C.$ in 5 min and finally becomes constant at ${50}^{\circ }C.$ Assume that the rate of loss of heat is directly proportional to the excess temperature over the surrounding then

• A. the rate of loss of heat of the cylinder to the surrounding at ${50}^{\circ }C.$ is 15 W .
• B. the rate of loss of heat of the cylinder to surrounding at ${30}^{\circ }C.$is 5 W.
• C. the rate of loss of heat of the cylinder to the surrounding at ${50}^{\circ }C.$ is 5 W.
• D. the rate of loss of heat of the cylinder to surrounding at ${30}^{\circ }C.$ is 15 W.

Answer 1

Answer: (A), (B)

The correct options are
A the rate of loss of heat of the cylinder to the surrounding at ${50}^{\circ }C.$ is 15 W .
B the rate of loss of heat of the cylinder to surrounding at ${30}^{\circ }C.$is 5 W.