Type P241B coaxial cable has an inductance of 0.4 μH/m and a capacitance of 40 pF/m.
The diagram below shows a 100 m length of this cable connected to a battery and switch at the sending end and a 50Ω resistor at the receiving end.
(a) If S is closed, what initial current will flow from the battery?
(b) How long will it take before this current changes?
(c) What will be the battery current at t=∞?
The Attempt at a Solution
I calculated the effective resistance of the cable to be 100 ohms. Since this is in series with a 50 ohm resistor then the total resistance is 150.