What is the potential difference across the 3 Ω resistor?

The correct answer to this question is 1v. Resistors are electrical components. Their purpose is to resist energy. They do so by limiting the flow of currents through a circuit.

Resistors can also be used to limit currents for the purpose of protecting electrical components, especially those components that have a risk of burning out at higher currents. Resistors are measured in the value of Ohm's, which is named after scientist Georg Simon Ohm.

The measurement of a resistor can be done by using an ohmmeter or a multimeter. There are many types of resistors, including electricity resistors, wire-round resistors, and carbon film resistors.