MCQ
Which of the following laws of thermodynamics defines the term internal energy?
- AZeroth law
- ✓First law
- CSecond law
- DThird law
✓
Answer
Correct option: B.
First law
b
(b)
(b)
Internal energy is the sum of all the energies of a molecule in the frame of reference of the system.
According to $1^{\text {st }}$ law,
$\Delta Q=\Delta U+\Delta W$
where $\Delta U$ is internal energy, $\Delta W$ is the work done and $\Delta Q$ is the heat transferred.
$\Delta U=\Delta Q-\Delta W$
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