Relation Between Watt and Volt

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Relationship Between Power and Voltage

Let’s suppose that there are two persons viz: P and Q, each of these is allocated a task of data analysis for a limited duration in which they have to fulfill the deadline. A person’s ability will be ascertained by how much time he takes. If person P meets the expectations of their hiring manager, he gets recruited into the company and if he does not, he fails.

So, here person P takes 2 hrs, while person Q takes 3 hrs, so here person P has more power than Q. 

Now, this person has ability but he needs a push, so that push or the driving force is the potential difference.  

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Relation Between Watt and Volt

From the above example, we inferred that power is the ability of person P to meet the deadline in 2 hrs. In terms of Physics, power is the rate of doing work and it is measured in Watts. 

We also understood that person Q also can meet the deadlines; however, the hiring manager gives him a driving force or the motivation to meet his expectations. Now, when ‘Q’ gets a voltage or motivation, he gets into the flow and completes the task in lesser time than before. 

In terms of Physics, the push is the potential difference between the time he took earlier and the time he took now to finish the task and it is measured in Volts.

Relationship Between Watt and Volt

In this undergoing interview process, when the hiring manager saw the caliber in Q and he motivated him to do the task. He could observe when ‘Q’ got ‘positivity’ (voltage), he did his work with an awesome flow. So, when the motivation (voltage) gets multiplied with his potential or ability, Q gets the power to work efficiently in 1.5 hrs, which was 3 hrs before. 

So, mathematically, we can express this statement in the following manner:

                   P = V * I……(1)

Equation (1) is the Volt Watt Equation.


P = power, which is measured in Watts

V = potential difference applied across the ends of the conductor through a source like a battery or a cell, which is measured in Volts

I = ‘I’ is the current that is the flow of electrons through the conductor or a wire and it is measured in Amperes or simply ‘A’.

Difference Between Watt and Volt

How Does Wattage Work?

Watt: An electrical power is measured in Watts. Let’s take our hose analogy.

Imagine you are spraying water from the hose into a bucket. So, here power is the measure of how quickly the bucket is filling up. 

From Watt and Volt equation, we understood that it is a straight-forward concept that power is the product of electric potential measured in volts and the current flowing through the conductor in Amperes. So, the more is the wattage, brighter is the light. 

We might have seen that a 9 W LED bulb is brighter than a 6 W LED bulb. 

Now, talking about voltage:

How Does Voltage Work?

Voltage: A force that makes electricity move is the voltage and it is measured in volts.

Let’s consider a hose analogy:

Imagine that voltage is the pressure in the garden hose, even if the nozzle of the hose is turned off, the pressure still persists inside it. 

So, in relation to the electricity, even if we switch off the bulb (as the bulb connected across the circuit), the voltage remains in the energized part of the circuit/ckt.

Volt and Watt Difference

Volts is the measure of the potential difference across the ends of the conductor or a conducting terminal of the wire.

Let’s have a look at equation (1):

 P = V * I

1 Watt  = 1 Volt * 1 Ampere


1 volt = \[\frac{1Watt}{1Ampere}\]....(2)

From eq (2), Watt is the rate at which the electrical work is performed when one ampere of current flows through the conductor on applying the potential difference of one volt across the ends of the conductor.

Now, let’s give a new meaning to the Watt and Volt Relation in terms of AC and DC:

Watt Volt Relation

Type of Current

Formula Used

Terms Used


PW = PF * VV * IA

PW = Power measured in Watts

PF = It is a power factor

VV = Voltage measured in volts

IA = Current measured in Amperes


PW = VV * IA

PWPower measured in Watts

VV = Voltage measured in volts

IA = Current measured in Amperes

Watt Related to Volt

The relation between Watt and Volt are direct. It means that Watt varies directly with the Volt. This implies the following things:

  • When the electric power in terms of Watt increases, the electric potential in terms of Volt increases with the same amount while keeping the electric current constant.

  • However, when the electric power Watts decreases, the electric potential in Volts decreases with the same amount, while keeping the electric current constant.

FAQ (Frequently Asked Questions)

Question 1: How Many Volts are in a Watt?

Answer:  When direct current or an alternating current is applied across the electrical circuit or in an alternating current circuit with a purely resistive equivalent load, one watt or W becomes equal to one volt (V) multiplied by one ampere (A), i.e., W = V * I.

Question 2: What is the Power of a Watt?

Answer: We define one watt as the energy required by one ampere of current to flow through the conductor on passing the potential difference of one volt through the conductor. The power is the product of the voltage and current, thus for measuring the power in watts, we need both volt and ampere.

Question 3: Describe the Terms ‘Watt’ and ‘Volt’.

Answer: The unit of Power was named after a renowned Scottish inventor and mechanical engineer named James Watt.

In terms of electromagnetism, the watt is the current flow of one ampere with a voltage of one volt. 

While the term ‘volt’ is a derived unit for electric potential, electromotive force, and electric potential difference. Since watt and volt have a direct relationship, which implies that change in the value of watt will affect the value of volt by the same magnitude.

Question 4: What is a Volt AMP?

Answer: Volt AMP or Volt-Amperes is an apparent power in an electrical circuit that is used in the context of AC circuits only.