2.) A 1200-mH inductor is connected in series with a 200-k2 resistor. This network can be either connected to or disconnected from a 25-V battery through the action of a switch. When the network is connected to the battery, the current in the circuit "charges;" when the network is disconnected from the battery, the current in the circuit "discharges." With the current initially zero, the network is connected to the battery for 12 us. Then, the network is disconnected from the battery for 18 s. (a) Calculate the time constant (in microseconds) of this circuit. (b) How much current (in microamperes) flows in the circuit at the end of this 30-us interval? (c) At what rate is the current changing (in amperes per second) at the end of this 30-s interval? (d) Graph the current flowing in the circuit as a function of time during this 30-us interval. Graph the rate at which the current is changing as a function of time during this 30-us interval.