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NEET-UG and JEE Main Physics · Class 11

Heat, work, internal energy and the first law — NEET & JEE Questions

Heat, work, internal energy and the first law is a topic in Thermodynamics, a Class 11 Physics chapter of the NEET-UG and JEE Main syllabus. TestBudy holds 12 published NEET-UG and JEE Main questions on Heat, work, internal energy and the first law, each with the marking scheme of the real paper.

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Heat, work, internal energy and the first law MCQs with solutions

10 of the 12 published questions on this topic, exactly as they appear in a test. Answers and worked solutions come with your result rather than on this page.

  1. Question 1 · difficulty L1 · recall

    Using the convention that work done by the system is positive, the first law of thermodynamics is

    • A. ΔU=Q−W\Delta U=Q-W
    • B. ΔU=Q+W\Delta U=Q+W
    • C. ΔU=W−Q\Delta U=W-Q
    • D. ΔU=0\Delta U=0 always
  2. Question 2 · difficulty L2 · understanding

    Internal energy is a

    • A. state function
    • B. path function
    • C. vector quantity
    • D. quantity defined only for ideal gases
  3. Question 3 · difficulty L2 · understanding

    Heat and work are best described as

    • A. modes of energy transfer
    • B. state functions stored in a system
    • C. identical to internal energy
    • D. properties defined at a single equilibrium state
  4. Question 4 · difficulty L2 · understanding

    For an adiabatic process,

    • A. Q=0Q=0
    • B. W=0W=0
    • C. ΔU=0\Delta U=0 always
    • D. temperature is always constant
  5. Question 5 · difficulty L3 · application

    A system absorbs 100 J of heat and does 40 J of work. What is the change in internal energy?

    • A. +60 J
    • B. +140 J
    • C. -60 J
    • D. -140 J
  6. Question 6 · difficulty L3 · application

    A gas loses 50 J of heat and has 20 J of work done on it. Using ΔU=Q−W\Delta U=Q-W with W as work done by the gas, what is ΔU\Delta U?

    • A. -30 J
    • B. -70 J
    • C. +30 J
    • D. +70 J
  7. Question 7 · difficulty L3 · application

    In an adiabatic compression, work is done on a gas. What happens to its internal energy?

    • A. It increases
    • B. It decreases
    • C. It must remain zero
    • D. It is undefined
  8. Question 8 · difficulty L3 · application

    A system undergoes a cyclic process and returns to its initial state. What is the net change in internal energy?

    • A. Zero
    • B. Positive
    • C. Negative
    • D. Equal to total heat only
  9. Question 9 · difficulty L4 · application

    During an isochoric process, a gas absorbs 200 J of heat. If only pressure-volume work is possible, what is ΔU\Delta U?

    • A. +200 J
    • B. 0
    • C. -200 J
    • D. +400 J
  10. Question 10 · difficulty L4 · application

    A gas expands and does 300 J of work while its internal energy decreases by 100 J. How much heat was supplied to the gas?

    • A. 200 J
    • B. 400 J
    • C. -200 J
    • D. -400 J

Common mistakes in Heat, work, internal energy and the first law

Recorded against questions in this topic that are not shown above, so none of these points at an answer you can see on this page.

  • Adds Q and $\Delta U$ instead of subtracting.
  • Assumes heat is the same for both paths because the endpoints are the same.

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