Question

What is the value of the potential difference between live wire and neutral wire?
$
  {\text{A}}{\text{. 440V}} \\
  {\text{B}}{\text{. 220V}} \\
  {\text{C}}{\text{. 520V}} \\
  {\text{D}}{\text{. 400V}} \\
 $

Answer 1

Hint: Here, we will proceed by mentioning all the different types of wires present in any circuit. Then, we will discuss the live as well as neutral wires in any circuit. Finally, we will define potential differences and write down the required potential differences.

Complete answer:
In any domestic circuit, there are in total three different types of wires which are neutral wire, earth wire and live wire.
The live and neutral wire's voltage varies depending on the location and also on the site within a region. Neutral wire doesn't have necessarily zero charge on them. The general idea is that live wire provides the voltage and the return wire is basically neutral wire. The live wire is at the required voltage in most installations and the neutral wire is attached to the ground at some point (so zero volts relative to the ground). Neutral wires are however still connected to the live wire in the device being operated because if the device is on, the voltage close to the device will not be zero. However, the carrying of a voltage relative to ground (for example, 130 Volts) is not unusual in Europe for both the live wire and the neutral wire, obviously with different phases providing approximately 240 Volts of supply relative to one another. You can see a fuse on both the live and neutral wire in this case and you'll get a shock from both, even though no system is plugged-in or switched-on to complete the circuit.
The potential difference is the difference between two points in a circuit in the amount of energy that the charge carriers have. The potential difference is equal to the value of current multiplied by the resistance and is also known as voltage.
The potential difference between live wire and neutral wire is 220 V.

So, the correct answer is “Option B”.

Note:
In this particular problem, we have to find the potential difference between the live wire and the neutral wire which can be practically done by connecting a voltmeter across the two points (in which one point lies on the live wire and the other point lies on the neutral wire).