How do you find the current function of time?

The current as a function of time can be found by taking the time derivative of the charge: I(t)=−QRCe−t/τ. The negative sign shows that the current flows in the opposite direction of the current found when the capacitor is charging. Figure 10.6.

What is current when capacitor is fully charged?

When a capacitor is fully charged, no current flows in the circuit. (i.e), the charging current drops to zero, such that capacitor voltage = source voltage.

What is time constant in capacitor?

The time constant of a series RC (resis-tor/capacitor) circuit is a time interval that equals the product of the resistance in ohms and the capacitance in farad and is symbolized by the greek letter tau (τ). The time in the formula is that required to charge to 63\% of the voltage of the source.

What is the time constant of a capacitor?

The time constant of a resistor-capacitor series combination is defined as the time it takes for the capacitor to deplete 36.8\% (for a discharging circuit) of its charge or the time it takes to reach 63.2\% (for a charging circuit) of its maximum charge capacity given that it has no initial charge.

Why does it take 5 times the voltage to discharge a capacitor?

It takes 5 times constant to charge or discharge a capacitor even if it is already somewhat charged. The capacitor voltage exponentially rises to source voltage where current exponentially decays down to zero in the charging phase. As the switch closes, the charging current causes a high surge current which can only be limited by the series

What is the time constant of a capacitor series?

τ τ = time constant (seconds) The time constant of a resistor-capacitor series combination is defined as the time it takes for the capacitor to deplete 36.8\% (for a discharging circuit) of its charge or the time it takes to reach 63.2\% (for a charging circuit) of its maximum charge capacity given that it has no initial charge.

How do you calculate the maximum charge on a capacitor?

When the key is pressed, the capacitor begins to store charge. If at any time during charging, I is the current through the circuit and Q is the charge on the capacitor, then RI + Q/C = ε … (1) When Q = Q 0 (the maximum value of the charge on the capacitor), I = 0 Q 0 / C = ε … (2) From equations.

How do you find the voltage and current of a capacitor?

To find the voltage and current of the capacitor at any instant, use the following capacitor discharging equation: v c = E e − t R C i c = E R e − t R C Current through the capacitor during discharging phase