# Formula Charging Capacitor Capacitor voltage    Source voltage    Capacitance    Electrical Resistance    Time ## Capacitor voltage

Unit
Voltage across the capacitor (e.g. between the two capacitor plates). When charging the capacitor, this voltage increases exponentially with time $$t$$. At the end of the charging process it reaches the value given by the source voltage $$U_0$$.

## Source voltage

Unit
Source voltage is the constant voltage applied to the capacitor.

## Capacitance

Unit
Capacitance is a characteristic quantity of the capacitor and tells how many charges must be brought onto the capacitor to charge the capacitor to the voltage $$1 \, \text{V}$$.

## Electrical Resistance

Unit
Resistor with the value $$R$$ connected in series with the capacitor. The resistor has an influence on how fast the capacitor can charge.

## Time

Unit
After the source voltage $$U_0$$ is applied, the capacitor starts to charge. The more time $$t$$ has elapsed, the closer the capacitor voltage $$U_{\text C}(t)$$ is to the value of the source voltage $$U_0$$.