Question

Heat is given to an ideal gas in an isothermal process. Then

A. internal energy of the gas will decrease.

B. internal energy of the gas will increase.

C. internal energy of the gas will not change.

D. the gas will do negative work.

• A. B
• B. C
• C. D
• D. A

Hint:

In an isothermal process the temperature is constant, and the internal energy of an ideal gas depends only on temperature.

Answer 1

The Correct Option is B

Step 1: Check statements A and B
Both say the internal energy changes, but the temperature is constant, so they are false.

Step 2: Check statement D
Heat is supplied, so $Q \gt 0$. With $\Delta U=0$, $W=Q \gt 0$, so the gas does positive work and D is false.

Step 3: Conclusion
Only statement C holds.

Final Answer:
Only the statement about unchanged internal energy is correct. \[ \boxed{\text{(B) }\text{internal energy of the gas will not change}} \]