Capacitor in parallel in a D.C. circuit.

Capacitor in parallel in a D.C. circuit. When switch S1 is closed, 12 V.D.C. is put across a 360 ohm slidewire rheostat. Moving the slider on the rheostat varies the voltage at 'A' from 0 to 12 V. When capacitor C (360 micro f) is not in the circuit (switch S2 open), rapidly moving the rheostat slider causes voltmeters 1 and 2 to swing quickly and equally to read voltage changes. When C is in the circuit (S2 closed), voltmeter 1 swings quickly to read voltage changes, but voltmeter 2 responds slowly. Thus, when C is in the circuit, time variations are smoothed out.