Imagine if the unknown resistor was very small ... don’t matter much because the voltmeter is essentially an open circuit. No current flows so, therefore, there’s no voltage drop across ...

This technique uses the two extra wires to control a balance voltage that keeps the current between the unknown resistor and the rest of the circuit at zero. This prevents current flowing except ...

Its main purpose is to slow down current surges or spikes by temporarily storing energy in an electro-magnetic field and then releasing it back into the circuit. Resistor The resistor is a passive ...