Multiple choice

A 30-Volts battery with zero source resistance is connected to a coaxial line of characteristic impedance of 50 Ohms at t = 0 second terminated in an unknown resistive load. The line length is that it takes 400 Js for an electromagnetic wave to travel from source end to load end and vice-versa. At t = 400ى s, the voltage at the load end is found to be 40 Volts.

The steady-state current through the load resistance is

  1. 1.2 Amps

  2. 0.3 Amps

  3. 0.6 Amps

  4. 0.4 Amps
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In steady state, the transmission line acts as a short circuit. Total circuit resistance = R_source (0Ω) + R_L = 100Ω. Current I = V/R = 30V/100Ω = 0.3A. The transient behavior settles to DC values determined only by source and load resistance.

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