Find the time after which current in the circuit becomes `80%` of its maximum value

If maximum energy is stored in capacitor at t = 0 then find the time after which current in the circuit will be maximum.

If maximum energy is stored in capacitor at t = 0 then find the time after which current in the circuit will be maximum.

A charged capacitro and an inductor are connected in series. At time t = 0 , the current is zero but the capacitor is charged, If T is the period of resulting oscillations, then the time after which current in the circuit becomes maximum , is

In adjacent circuit, switch S is closed at t = 0. The time at which current in the circuit becomes half of the steady current is

A circuit consists of a coil, a switch and a battery, all in series. The internal resistance of the battery is negligible compared with that of the coil. The switch is originally open. It is thrown closed, after a time interval Deltat . The current in the circuit reaches 80.0% of its final value. The switch then remains closed for a time interval much longer than Deltat . The wires connected to the terminals of the battery are then short circuited with another wire and removed from the battery, so that the current is uninterrupted. At an instant that is a time interval Deltat . After the short circuit, the current is what percentage of its maximum value? a)20% b) 8% c) 4% d)10 %

If at t = 0 the switch S_(w) is closed , then the charge on capacitor (initially unchanged)in the given circuit when the current through battery becomes 50 % of its maximum value is (assume battery is ideal)