Question

In a device, the complete conversion of heat energy into mechanical work ________.

• A. is not possible at any cost
• B. depends on the type of device in use
• C. depend on the atmospheric temperature, pressure etc
• D. depends on the type of fuel used

Answer 1

The correct option is A is not possible at any cost

The second law of thermodynamics The Kelvin–Planck statement (or the heat engine statement) of the second law of thermodynamics states that it is impossible to devise a cyclically operating device, the sole effect of which is to absorb energy in the form of heat from a single thermal reservoir and to deliver an equivalent amount of work.[1] This implies that it is impossible to build a heat engine that has 100% thermal efficiency.

In a device, the complete conversion of heat energy into mechanical work is not possible at any cost.

Option A is correct