Question

When heat is given to a gas in an isobaric process, then?
A. The work is done by the gas
B. Internal Energy of the gas increases
C. Both (A) and (B)
D. None of these (A) and (B)

Answer 1

Hint: An isobaric process, or a thermodynamic process where the system's pressure stays constant, is one in which a thermodynamic process is taking place at constant external pressure, or $\Delta P = 0$. Hence, use the scientific approach and fundamentals to state the answer for the given problem.

Complete step by step solution:
We know that in an Isobaric process, pressure remains constant and change in pressure is zero i.e., $\Delta P = 0$.

Now, when heat is supplied to gas at constant pressure, there will be two scenarios: -
- a part of the heat is used in the expansion of gas, and
- Another remaining part of heat will contribute to increasing the temperature of gas which will result in increase in the internal energy of the gas.

Thus, when heat is given to a gas in an isobaric process, then the work is done by the gas, and the Internal Energy of the gas increases as well.

Hence, the correct option is C.

Note: When heat is transmitted to the system in an isobaric process, some work is done. However, there is a shift in the system's internal energy. This also implies that no quantities, as stated in the first law of thermodynamics, reach zero.