Q168 / 200 · MHT CET - Medical 2026 (21 April Shift 1) · Physics
For a cyclic thermodynamic process
- A$Q = -W$ and $\Delta U \neq 0$
- B$Q = 0$ and $\Delta U = 0$
- C$Q \neq 0, \Delta U \neq 0$
- Correct answerD$Q = W$ and $\Delta U = 0$
Solution
For a cyclic thermodynamic process, the initial and final states of the system are the same.
Since internal energy $U$ is a state function, the change in internal energy over a complete cycle is zero, so $\Delta U = 0$.
According to the first law of thermodynamics, $Q = \Delta U + W$.
Substituting $\Delta U = 0$, we get $Q = W$.
Therefore, for a cyclic process, $Q = W$ and $\Delta U = 0$.
Answer: $Q = W$ and $\Delta U = 0$
Since internal energy $U$ is a state function, the change in internal energy over a complete cycle is zero, so $\Delta U = 0$.
According to the first law of thermodynamics, $Q = \Delta U + W$.
Substituting $\Delta U = 0$, we get $Q = W$.
Therefore, for a cyclic process, $Q = W$ and $\Delta U = 0$.
Answer: $Q = W$ and $\Delta U = 0$
Hence, the correct answer is option: 'D'.