Difference Between in Physics

Difference Between Voltage and Current

In electricity, current and voltage are two fundamental quantities. As voltage is the cause of an event and current is the effect of that event. The difference between voltage and current can help us to understand the basics better and know their comparisons thoroughly. Let us now understand what is the difference between voltage and current.

What is Voltage?

The electrical force that would drive an electric current between two points is termed as voltage. “V” represents voltage.

What is Current?

The rate at which electric charge flows past a point in a circuit is termed as current. “I” represents current.

Difference between Voltage and Current 

difference between voltage and current

                                                           difference between voltage and current

The important difference between voltage and current.

Parameters Voltage Current
Definition Voltage is the potential difference between two points in an electric field, which causes current to flow in the circuit. Current is the rate of flow of electrons is called current.
Symbol Voltage is represented by “V” Current is represented by “I”
Unit Volt “V” Ampere “A”
Unit Charge 1 Joule / Coulomb = 1 Volt 1 Coulomb / Second = 1 Ampere
Formula V = W / Q

Voltage = Work done / Charge

I = Q / t

Current = Charge / Time

Cause & Effect Voltage is the cause of current (being an effect). Current is the effect caused by Voltage.
Measuring Instrument To measure the value of voltage by connecting it in parallel we use voltmeter. To measure the value of current by connecting in series we use ampere meter.
Types Alternating Voltage and Direct Voltage Alternating Current (AC) and Direct Current (DC)
Field Produced Magnetic Field Electric Field (Electrostatic)
Produced by Generator, Alternator and Batteries Voltage and EMF
Drop and Loss Due to Impedance (AC Resistance) Due to Passive elements
Series Connection Unequal in all components


Equally distributed in all components
Parallel connection Magnitude of voltage remain same in all componets Magnitude of current vary in all components
Polarity Changes Alternating Voltage changes its polarity and magnitude while it is remain constant in DC. Alternating Current changes its polarity while Direct Current does not changes its polarity.
Existence Voltage can exist without current, as it is the cause of flowing charge. Current does not exist without voltage, as voltage is the main cause to flow current except theoretical superconductor.

After learning about the difference between voltage and current, it is important to know the details of voltage and current thoroughly.


The electrical potential difference between two points is the voltage between those two points. Voltage is the electromotive force, which is responsible for the movement of electrons or electric current through a circuit. The potential for each Coulomb of electric charge to do work represented by voltage.

A voltage produces an electrostatic field. As the voltage increases between two points, the electrostatic field becomes more intense. As the distance increases between two points having a given voltage with respect to each other, the electrostatic intensity decreases between the points.

There are two basic types of voltages i.e. Alternating Voltage and Direct Voltage

Alternating Voltage: Voltage, which changes its direction and magnitude, continuously throughout the time, is termed as AC voltage. Alternators can generate alternating voltages.

Direct Voltage: DC Voltage has the constant magnitude, which does not change its polarity throughout the time. Electrochemical cells and batteries can generate direct voltage.


In electric circuits, current is the flow of electric charge. Electric current are the electrons or negatively charged particles that move around in circuits. So when current flows in some direction in a circuit, the actual physical effect is electrons flowing in the opposite direction.

It is represented by the symbol “I”. The SI unit of current is ampere, which is denoted by “A”. If one coulomb charge passes through a conducting point in one second, the amount of current is known as one ampere.

There are mainly two types of currents i.e. AC and DC (Alternating Current & Direct Current).

AC Current: Current which changes its direction and magnitude continuously throughout the time is termed as alternating current.

DC Current: Current, which has the constant magnitude and does not change its polarity or direction throughout the time, is termed as direct current.


Q1. What is a short circuit?

Answer: A short circuit is an unwanted connection of very low resistance such as a wire, which provides a very easy path for current. We can consider it as an electrical short cut. We use short circuit to describe a fault or accidental connection rather than a deliberate one.

Q2. What is the relation between voltage and current?

Answer: The relationship between the voltage, current, and resistance in an electric circuit is described by Ohm’s Law: i = v/r means current is directly proportional to the voltage .




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