Current Electricity

Many inventions and discoveries have been made in order to facilitate human life smoothly. The discovery of current electricity is one such discovery that we are highly dependent on to make our life easier. Benjamin Franklin is credited with the discovery of electricity.

What Is Current Electricity?

Current electricity is defined as the flow of electrons from one section of the circuit to another.

Electromotive Force (EMF) and Voltage:

When two bodies at different potentials are linked with a wire, free electrons stream from Point 1 to Point 2, until both the objects reach the same potential, after which the current stops flowing. Until a potential difference is present throughout a conductor, current flows.

From the above analogy, we can define electromotive force and voltage as follows:

Electromotive Force Definition: Electromotive force is defined as the electric potential produced by either an electrochemical cell or by changing the magnetic field.

Voltage Definition: Voltage is defined as the electric potential difference between two points.

Types of Current Electricity

There are two types of current electricity as follows:

• Direct Current (DC)
• Alternating Current (AC)

Direct Current

The current electricity whose direction remains the same is known as direct current. Direct current is defined by the constant flow of electrons from a region of high electron density to a region of low electron density. DC is used in many household appliances and applications that involve a battery.

Alternating Current

The current electricity that is bidirectional and keeps changing the direction of the charge flow is known as alternating current. The bidirectionality is caused by a sinusoidally varying current and voltage that reverse directions, creating a periodic back and forth motion for the current. The electrical outlets at our home and industries are supplied with alternating current.

What is an Alternating Current (AC)?

In alternating current, the electric charge flow changes its direction periodically. AC is the most commonly used and most-preferred electric power for household equipment, office, buildings, etc. It was first tested based on the principles of Michael Faraday in 1832 using a Dynamo Electric Generator.

Alternating current can be identified in a waveform called a sine wave. In other words, it can be referred to as a curved line. These curved lines represent electric cycles and are measured per second. The measurement is read as Hertz (Hz). AC is used in powerhouses and buildings because generating and transporting AC across long distances is relatively easy. AC is capable of powering electric motors which are used in refrigerators, washing machines, etc.

What is Direct Current (DC)?

Unlike alternating current, the flow of direct current does not change periodically. The current electricity flows in a single direction in a steady voltage. The major use of DC is to supply power to electrical devices and also to charge batteries. Example: mobile phone batteries, flashlights, flat-screen television and electric vehicles. DC has the combination of a plus and a minus sign, a dotted line or a straight line.

Everything that runs on a battery and uses an AC adapter while plugging into a wall or uses a USB cable for power relies on DC. Examples would be cellphones, electric vehicles, flashlights, flat-screen TVs (AC goes into the TV and is converted into DC).

Alternating Current	Direct Current
AC is easy to be transferred over longer distances – even between two cities – without much energy loss.	DC cannot be transferred over a very long distance. It loses electric power.
The rotating magnets cause the change in direction of electric flow.	The steady magnetism makes DC flow in a single direction.
The frequency of AC is dependent upon the country. But, generally, the frequency is 50 Hz or 60 Hz.	DC has no frequency or zero frequency.
In AC the flow of current changes its direction forward and backward periodically.	It flows in a single direction steadily.
Electrons in AC keep changing their directions – backward and forward.	Electrons only move in one direction –  forward.

Generation of Current Electricity

Current electricity can be generated by the following methods:

• By moving a metal wire through a magnetic field (Both alternating current and direct current can be generated by the following method)
• By a battery through chemical reactions (Direct current can be generated through this method)

Relative Motion Between Magnetic Field and Coil

Note that this setup must be a part of an electric circuit, otherwise the electrons have nowhere to go and current electricity won’t be generated.

The direction of the magnetic field and the direction of the wire will determine the direction of the current through the wire.

Current Electricity vs Static Electricity

In this section, we will look into the difference between current electricity and static electricity:

What Is Static Electricity?

Static electricity refers to the electric charges that build up on the surface of materials or substances. These charges remain static until they are grounded, or discharged. This type of electricity is formed due to fiction. Basically, the phenomenon of static electricity arises when the positive and negative charges are separated.

Now let us look at the various differences between static electricity and current electricity.

Current Electricity	Static Electricity
The electricity due to the flow of electrons is known as current electricity.	The electricity built on the surface of a substance is known as static electricity.
Current electricity is generated by power plants and batteries.	Static electricity is generated when objects are rubbed against each other resulting in charge transfer.
Current electricity is controlled.	Static electricity is uncontrolled.
The electricity that is used to power up electronic devices is an example of current electricity.	The shock experienced while touching a doorknob is an example of static electricity.

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