A circuit consists of a 24 V ideal battery connected in series with a 105 Ω resistor and a 0.30 H inductor. The switch in the circuit has been open for an extended period of time. At t=0 s, the switch is closed. Calculate the steady-state current established in the circuit.

A wire is coiled 750 times to form a 35 cm solenoid with an inductance of 150 mH. When a current I passes through the solenoid, it produces a magnetic field inside the inductor. When the solenoid is suddenly disconnected from the voltage and connected to a resistor R, the strength of the magnetic field decreases by a factor of 4 in 250 μs. Calculate the value of R.

A circuit consists of a resistor with resistance R_a and an inductor with inductance La connected in series to an ideal battery. Initially, the switch is open and no current flows through the circuit. At t=0, the circuit's switch abruptly closes. Determine the expression for the transient current as a function of time t in terms of R_a, L_a, and the steady-state current I_s.

Consider an LR series circuit connected to an AC power source. The circuit consists of a resistor with a value of 100 Ω and an inductor with an inductance of 100 mH. Determine the crossover frequency.