[Physics Class Notes] on Difference Between Watts and Volts Pdf for Exam [2024]

Watts is the SI unit of power, and Volts is the SI unit of potential difference.

When we go to the electricity shop, we find a 9 Volt battery, 9 Watts bulb, and so on. However, we come across a question as to why there are so many units like Watts, Volts, Ampere, etc.

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The units like Watts and Volts have a difference.

Power is measured in Watts, while voltage in Volts. There is a difference between Watts and Volts. In this article, we will learn about the difference between Watts and Volts in a detailed manner.

Difference Between Watts and Volts

Now, let’s discuss the difference between Watt and Volt in tabular form:

Watts and Volts

Parameters	Watts	Volts
Definition	Power is the work/job done by an object in a unit of time.	Voltage is called the electric tension, which pushes charged electrons in the circuit. The potential difference between the two points is measured by the amount of work done in moving a charge from one point to the other.
SI unit	Watt is the SI unit of power.	Volt is the SI unit of the potential difference and the electromotive force.
Symbol	The notation for the unit of power is W.	The symbol for the unit of potential difference is V.
Measurement	In measuring realistic power, we use the unit of Watts.	To measure the small amount of voltage from the power supply.
Measuring instrument or device	The device used for measuring power is the power meter.	The device used for measuring the voltage in Volts is the Voltmeter.
Base unit	The base unit of Watts is kgm2s-3	The base unit of Volts is kgm2A-1s-3
The device needed for measurement	The wattmeter is a typical multimeter that measures watts unless both V and I are DC.	The voltage applied across the ends of the conductor does the work in pushing current from one end to the other in a particular direction. The device that measures the potential difference is called the voltmeter. The voltmeter is connected parallel to the circuit.
Dimensional Formula	The dimensional formula for Watts is: [M1L2T-3]	The dimensional formula for Volts is: [M1L2T-3A-1]

What is Power?

The amount of work a body can do in a unit of time is called power. In simple words, power is the rate of performing any task.

The formula for power is :

Power = Work/Time

Thus the power of an agent measures how quickly it can do the work/job. When you take less time in doing any work, it means you have great power. If in case, you take a large amount of time to do the same work, it means you have less power.

So, power is inversely proportional to time.

There are various formulas for power; these are:

V x I

In unit: Volts x Ampere

Volt-ampere is the apparent power.

In unit: Work/time

Joule per second

P = F . v

In unit: Force x velocity

N . m/s

What is Voltage?

Voltage is called the electric tension or the electrical pressure, which pushes charged electrons from one end to the other in a specified direction inside the circuit.

On connecting the battery to the circuit, the potential difference develops across the two points of the circuit. The difference developed, leads to the pushing of an electron.

So, the potential difference between the two points is measured by the amount of work done in moving a charge from one point to the other.

There are various formulas for voltage; these are:

In unit: Watt/Ampere

In unit: Ampere x Ohm

In unit: Joule per coulomb

Difference Between Watts and VA

The below table lists the difference between Watts and Volt Ampere: