First Law of Thermodynamics Practice
10 problems · instant feedback · full explanations
ΔU = Q − W (physics sign convention): heat in raises internal energy, work done by the system lowers it. Track the signs carefully.
Q1.
The first law of thermodynamics is a statement of:
Multiple choice · Easy
Q2.
A gas absorbs 500 J of heat and does 200 J of work on its surroundings. What is the change in internal energy?
Numerical answer (J) · Medium
Q3.
A gas expands adiabatically (no heat exchange) doing work. Its temperature:
Multiple choice · Medium
Q4.
In which process is the work done by a gas zero?
Multiple choice · Easy
Q5.
A system loses 50 J of heat and does 100 J of work. Find ΔU (physics sign convention).
Numerical answer (J) · Hard
Q6.
For an isothermal expansion of an ideal gas:
Multiple choice · Medium
Q7.
Internal energy is a state function: it depends only on the system's current state.
True / False · Easy
Q8.
A hot object 'contains' a certain amount of heat.
True / False · Medium
Q9.
Over one complete thermodynamic cycle, the net heat absorbed equals:
Multiple choice · Hard
Q10.
2 kg of water absorbs 8368 J and warms by 1 K. What is the specific heat capacity?
Numerical answer (J/kg·K) · Hard