Question

Circuits:
A technician at A measures the current I the moment the switch is thrown (t=0) and finds it to be 2A. He measures it again in a long time later and finds it to be 1A. What is in the black box? Explain, in your own words, why the two measurements are different and what is happening in each case.

Answer 1

If I were to guess, I'd say the circuit consists of a resistor (or some load) and a capacitor in parallel with each other.

The key to this question is that the current drops after "a long time". To me, this implies that there is a capacitor in the circuit that's being charged. While it's charging the circuit will draw more current...and after a long time it will be fully charged so the current will drop. At that point it's only feeding a 1A load.