Isochoric - Of equal or constant
volume, usually applied to a thermodynamic process during which the volume of
the system remains
unchanged.
For an isochoric process: all the
heat being transferred to the system is added to the system's internal energy.
If the quantity of gas stays
constant, then this increase in
energy is proportional to an increase in temperature.
On a P-V diagram, an isochoric
process appears as a straight vertical line.
Because there is no area under such a
line, or in other words no work is done, by or on, the thermodynamic system in
an isochoric process. The first law of thermodynamics thus implies that the
change in internal energy exactly matches the heat flow:
Isobaric (Constant Pressure)
Isochoric (Constant Volume)
Isothermal (Constant Temperature)