The SI unit of Potential Difference is _____

A. Ohm

B. Ampere

C. Ohm-meter

D. Volt

The correct answer is D. Volt. The SI unit of potential difference is the volt (V), named after the Italian scientist Alessandro Volta, who invented the electric battery. The potential difference, commonly known as voltage, is a crucial concept in electricity and electronics. It refers to the difference in electric potential between two points in a circuit, which causes an electric current to flow.

Complete Explanation

Potential Difference is the work done to move a unit charge from one point to another in an electric circuit. It is measured in volts (V) and determines the strength of an electric source, like a battery or power supply. Potential difference is mathematically defined as:

Where:

V = Potential difference (volt)
W = Work done (joule)
Q = Charge (coulomb)

This means that 1 volt is the potential difference when 1 joule of work is done to move 1 coulomb of charge.

Why Are the Other Options Incorrect?

A. Ohm (Ω): The SI unit of electrical resistance

B. Ampere (A): The SI unit of electric current

C. Ohm-meter (Ω·m): The SI unit of electrical resistivity

Thus, the correct choice is (d) Volt.

Real-Life Examples of Potential Difference

• Batteries: A 9V battery provides a potential difference of 9 volts between its terminals.
• Wall Sockets: In most countries, home electrical outlets supply 110V or 220V to operate devices.
• Lightning: A thundercloud builds up millions of volts of potential difference before striking as lightning.

Common Doubts

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