일반물리학 2 — Induction and Inductance: Problem 27

27 A solenoid having an inductance of 9.70 mH is connected in series with a 1.20 k\(\Omega\) resistor. (a) If a 14.0 V battery is connected across the pair, how long will it take for the current through the resistor to reach 40.0% of its final value? (b) What is the current through the resistor at time \( t = 0.50\tau_L \)?