Considering the RC Network shown in Figure 5.1, we can use KCL to write Equation (5.1). R C Vo(t) Figure 5.1 Source-free RC Network C i.e., dv o ( t ) v o ( t ) + =0 dt R (5.1) dv o ( t ) v o ( t ) + =0 dt CR If Vm is the initial voltage across the capacitor, then the solution to Equation (5.1) is v 0 (t ) = Vm e where t − CR (5.2) CR is the time constant Equation (5.2) represents the voltage across a discharging capacitor. To obtain the voltage across a charging capacitor, let us con