Voltage and why voltage cannot change instantaneously in capacitor but current but why current cannot change instantaneously in inductor. Thank you in advance.
The formula i = C dV/dt says that the current thru a capacitor is equal to capacitance multiplied by dV/dt. To change voltage instantaneously (infinite dV/dt) the current must be infinite.
To formula V = L di/dt says that the voltage across an inductor is equal to inductance multiplied by di/dt. To change current instantaneously (infinite di/dt) the voltage must be infinite.
changing the current or voltage instantaneously means (dt=0approximately) i.e the slop (dv/dt or di/dt) goes to infility . then i(for the c) or v(for the inductor) should be infinite.
dv/dt is the change of the voltage with respect to time. Remember that capacitors are open when applied with a DC voltage. A DC voltage has dv/dt = 0, which means that there is no change in its voltage. Applying it in the equation i = C dV/dt, current would be zero. The contrary applies to inductors. Please check on the capacitor/inductor graphs for more info.