reciprocal relation वाक्य

In fluid systems described in terms of temperature, matter density, and pressure, it is known that temperature differences lead to heat flows from the warmer to the colder parts of the system; similarly, pressure differences will lead to matter flow from high-pressure to low-pressure regions ( a " reciprocal relation " ).
The theory developed by Onsager is much more general than this example and capable of treating more than two thermodynamic forces at once, with the limitation that " the principle of dynamical reversibility does not apply when ( external ) magnetic fields or Coriolis forces are present ", in which case " the reciprocal relations break down ".