Difference between Voltage and Current: Explained With Definitions, and Types

Voltage plays an important role that is responsible for the potential difference in a conducting material and for the flow of electrons. This flow of electrons eventually generates an electric current and we get a working electric circuit. Both of these concepts are interrelated with each other for a circuit to function and also distinctive enough for us to understand the difference between voltage and current. Voltage represents the electrical potential difference between two points, while current represents the flow of electric charge between two points. This is the main difference between voltage and current.

In this article, we will study in brief the difference between Voltage and Current, understand the concept, its comparison with respect to power, and its wide uses.

Difference between Voltage and Current

The table below shows the difference between voltage and current.

Voltage	Current
It is the potential difference produced between two charged points in a conductor.	It is the flow of free electrons in an electrical circuit.
The S.I. unit of voltage is volt and is measured using a voltmeter.	The S.I. unit for electric current is ampere and is measured using an ammeter.
Voltage is denoted by V	Current is denoted b I
Impedance causes loss of voltage.	Different passive elements in a circuit cause loss of current.
The formula for voltage (V) = IR	The formula for Current (I) = Q/t
The value of voltage remains the same across a parallel combination.	The value of current is the same in a series circuit.
Voltage creates an electrostatic field	Current creates a magnetic field
In a series circuit, the voltage across all the components is different	The current flowing through all the components in a series circuit remains the same
In a parallel circuit, the voltage across all the components remains the same	The current flowing through all the components in a parallel circuit is different
The voltage is the cause of the flow of current	The current is the effect of the voltage
Voltage between two points can exist without current	Current cannot exist without the voltage
The electric voltage is classified into two types− alternating voltage and direct voltage	The electric current is also classified into two types- alternating current and direct current

What is Voltage?

Voltage is the potential difference produced between two charged points in a conductor. It is the potential energy per unit charge and is represented by the symbol V. Its S.I. unit is volt and is named after Alessandro Volta. Ohm’s law gives a relationship between the potential difference and current flowing in a circuit as V = IR, which states the voltage across a circuit is directly proportional to the resistance and electric current flowing through it.

Types of Voltage

There are two types of voltage: AC voltage and DC voltage.

AC Voltage

• It is the potential difference between two terminals where an alternating current flows.
• It takes the form of the sine wave.
• In a single cycle, the AC voltage starts from 0V, reaches the required peak and comes back to 0V.
• It is generally expressed in two forms and .
• is the maximum amplitude of the sine wave and it is the mean average value of the square function given by the formula,

DC Voltage

• It is the potential difference between two terminals when a direct current is applied to the circuit.
• It generates no cycles or any sine wave.
• It has the ability to maintain a constant value of the voltage.
• The formula for direct voltage in an electrical circuit shall be given by Ohm’s law as V=IR where V =voltage and R = resistance and I = direct current flowing through the circuit.

What is Current?

Electric current is simply defined as the flow of free electrons in an electrical circuit also responsible for generating electricity. It is expressed by the amount of charge flowing through a particular area in a given time. In circuits constituting electric wires, the electrons constitute the free electrons constitute an electric current. Let Q+ be the net positive charge and Q- be the net negative charge flowing through a conductor. Hence, the current (I) across an area flowing in the forward direction at a given time T is given by, Q = I / T. Its S.I. unit is Ampere which is defined as the order of magnitude of currents and is named after Andre Marie Ampere.

Types of Current

In this article, we are going to discuss two types of current alternating current and direct current

Alternating Current

• In an alternating current, the current flows back and forth at regular time intervals.
• The frequency of the alternating current is between 50 to 60 Hz.
• An alternating current is transformed into a direct current with the help of a rectifier.
• To find the current flowing through a resistor, ,

Where, and if R is a constant,

The current amplitude

• The voltage and current are in phase with each other when passes through a pure resistor circuit.

Direct Current

• A direct current means the electrical current flows in one direction only and is consistent throughout the entire circuit.
• In a direct current, the net amount of charge flowing through a cross-sectional area shall be which is proportional to time “t”.
• For a direct current, the current density is the current flowing through per unit area.
• Direct current is transformed into an alternating current with the help of an inverter.

Relationship Between Voltage and Current

The relationship between voltage and current is described by Ohm's law, which is a fundamental principle in electrical circuits. Ohm's law states that the current flowing through a conductor is directly proportional to the voltage applied across it and inversely proportional to the resistance of the conductor. Mathematically, Ohm's law can be expressed as:

V = I * R

Where:
V is the voltage across the conductor (measured in volts, V).
I is the current flowing through the conductor (measured in amperes, A).
R is the resistance of the conductor (measured in ohms, Ω).

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