# GRE GR 1777, Problem 008 Solution

Physics GRE GR 1777

8. Thermodynamics (First law of thermodynamics)

Solution)

In the first law of thermodynamics,

$dQ = de + PdV$
where $Q$ is the amount of heat, $e$ is the internal energy, $P$ is the pressure, and $V$ is the volume of the system.

If we want to make a process that the increase in the internal energy is equal to the heat supplied, we should get rid of the second term of above equation. That means, $dV$ should be zero.

The process that the $dV$ equals zero is called the constant volume process, therefore the answer is (B).