In a circuit diagram, which point is considered to be at zero voltage?

In a circuit diagram, which point is considered to be at zero voltage?

• A. The hot line
• B. The neutral
• C. The ground reference
• D. The supply positive

Answer: (C)

Voltage is always measured relative to a reference point. In most circuit diagrams, the reference point is the ground, defined as zero volts. This ground node acts as a common baseline so all other voltages are described in relation to it. The ground reference is tied to the earth or chassis safety path, making it a stable zero-volt reference for analysis and safe operation. The neutral conductor is intended to be near ground potential, but because current flows through it, there can be a small voltage drop along the conductors. That means neutral is not guaranteed to be exactly zero volts in every situation. The hot line and the supply positive are at nonzero potentials relative to ground, typically much higher, so they are not zero.

Voltage is always measured relative to a reference point. In most circuit diagrams, the reference point is the ground, defined as zero volts. This ground node acts as a common baseline so all other voltages are described in relation to it. The ground reference is tied to the earth or chassis safety path, making it a stable zero-volt reference for analysis and safe operation.

The neutral conductor is intended to be near ground potential, but because current flows through it, there can be a small voltage drop along the conductors. That means neutral is not guaranteed to be exactly zero volts in every situation. The hot line and the supply positive are at nonzero potentials relative to ground, typically much higher, so they are not zero.