Current Electricity Formula, Definition, Equations with Examples

Electric current is used to operate cell phones, power trains and ships, run refrigerators, and power motors in machines like food processors. Electrical energy must be converted to other forms of energy, such as heat, light, or mechanical energy. Everything is made up of tiny particles called atoms. Atoms are made of smaller particles called protons, electrons, and neutrons. Atom has the same number of protons (having a +ve charge) and electrons (having a -ve charge). Sometimes electrons are moved away from atoms.

Electric current is the movement of electrons. This is moving through a wire, measured in amperes and refers to the number of accounts moving through a wire per second. For current flow, the circuit must be closed. In other words, there must be an uninterrupted path from the power source through the circuit and back to the power source.

Current Electricity

Many inventions and inventions have been made to make man’s life run smoothly. The invention of the current is an invention we rely on to make our lives easier. Benjamin Franklin is credited with discovering Electricity. Electric current, subatomic charged particles (e.g., negatively charged electrons, positively charged protons), ions, or holes (resulting from electron defects) are considered positive particles.

The electric current in a wire where the charge carriers are electrons measures the number of charges passing any point on the wire per unit of time. In alternating current, the movement of electric charges is periodically reversed; Not so in live broadcasts. In many cases, the current direction in electric circuits is considered to be the direction of positive charge flow opposite to the actual electron drift. The current so defined is called conventional current.

The symbol of ‘I usually denote current. Ohm’s law relates to the current flowing through a conductor to voltage V and resistance R. If V = IR. The alternative statement of Ohm’s law is I = V/R. Current in gases and liquids usually involves a flow of positive ions in one direction and a flow of -ve ions in the opposite direction. By considering the overall effect of the current. This direction is usually considered the positive charge carrier.

Electric Current Examples

1. Two Charged Conductors Separated by an Insulator:

Here two conductors are charged to different potentials. They are supported on insulating stands and placed at a distance. Due to the potential difference between these two conductors, there is no flow of electric charge between them because they are separated by air which is an insulator.

2. Two Charged Conductors Connected by Metallic Wire:

Now, these two conductors are connected by a metallic wire, and there is a net flow of charge from one conductor to the other at a lower potential. This flow continues until their electric potentials become equal.

• In the first case of lightning, there is a flow of charge from the clouds to the ground, resulting in a transient current. This current stops when the flow of charge stops.
• Constant charge flow in a cell-powered clock, torch etc.

Electric current SI Unit

electric amperes are denoted by ‘A’.

Where I = q/t = 1 coulomb/sec = 1A.

If 1 coulomb of charge per second flows through a section of wire, the current flows through the wire and is said to be one ampere.

The ampere is one of the seven fundamental units of physics.

Conventional Current Flow

Conventional current flow is the flow of Electricity from the positive terminal to the negative terminal of an external source, such as a battery. Here, the direction of the electron flows from the negative terminal and is opposite to the direction of the current as it moves toward the battery’s positive terminal. Therefore, conventional electric current is opposite to electron flow, while positive charge flow is in the electric current direction.

The magnetic field is the magnetic effect of electric currents and magnetic materials. The magnetic field at any particular point is specified by direction and magnitude (or strength). A vector field represents it. The magnetic effect of electric current means that an electric current traveling in a wire produces a magnetic field around it—iron, steel, nickel and cobalt.

The magnetic effect of electric current is the main effect of electric current in use. Without its applications, we would not have motors in the present world. The current-carrying conductor creates a magnetic field around it, which is absorbed by using magnetic lines of force or magnetic field lines. The nature of magnetic field lines around a straight current-carrying conductor is concentric circles with the center at the axis of the conductor.

Electric current has three effects. They are the magnetic, heating, and chemical effects determined by the deflection of the compass. A magnetic field has a direction and a magnitude.

 If an electric current flows from north to south, the magnetic compass deflects clockwise, indicating that the direction of the magnetic field depends on the direction of the electric current. Traditionally, the magnetic lines are thought to originate at the North Pole and converge at the South Pole.

Magnetic field lines from 2 magnets cannot cross each other as the current through the wire increases the magnitude of the magnetic field increases. The SI unit is the magnetic field is Tesla. Electricity and magnetism are restrained together, and it has been proved that when an electric current passes through a copper wire, it produces a magnetic effect.

Magnetic Field

• The magnetic field direction is generally considered to be the direction in which the compass needle’s north pole travels.

• Convergence is when the field lines originate at the North Pole and converge at the South Pole.
• Two-magnet bar field lines are not found to cross each other. If this occurs, it indicates the compass needle at the intersection points of the two directions, which is impossible.

Right-Hand Thumb Rule

• The right-hand rule of thumb, also known as Maxwell’s corkscrew law, describes the magnetic field direction associated with a current-carrying conductor.
• The right-hand rule of thumb says, “Imagine holding a current with a straight conductor in your right hand, so the thumb points are in the direction of the current. Then bend your conducting fingers toward the magnetic field lines.

Fleming’s Left-Hand Rule

Fleming’s left-hand rule states, “Extend the left thumb, index finger, and middle finger. These all are perpendicular to each other. If the first finger. It is the direction of the magnetic field, the second finger is in the direction of the current, the thumb is in the direction of motion or driving force.”

• The human body produces a magnetic field, but it is one billionth less than the magnetic field on Earth.
• The heart and brain are the two main organs that create the magnetic field in the human body.
• The magnetic field in the human body is the basis for obtaining images of different body parts.
• The technique used to obtain an image of a body part is called MRI magnetic resonance imaging.

Strength of Magnetic Field Lines

• The straight current-carrying conductor has a magnetic field in the shape of concentric circles. Magnetic field lines directly visualize the magnetic field of a current-carrying conductor.
• The direction of the magnetic field produced due to a current-carrying conductor depends on the direction of the current flows.
• The direction of the electric current is reversed, and the direction of the magnetic field is reversed.