Electric Current Formula 

What is Electricity?

• Electricity is the flow of electrons which is caused due to electrostatic force. It is the force that operates between charged particles.

• An atom consists of various orbits which have electrons in it. The charge of protons keeps the electrons glued to the atom. The closer the electrons to the nucleus, the more

strongly they are attracted to the center as compared to the electrons in the outer orbits. Also, the electrons repel each other.

• When a negatively charged electron is close to an atom, it repels the electron in the outermost orbit. Because of this repelling force, the electron will be ejected from the orbit and becomes a free electron. This free electron may get pulled to the orbit of a new atom.
• This incoming electron then repels the electron of this new atom and ejects it from the orbit.
• So the same process repeats with the next atom and a continuous flow of electric charge is established, which is the constant flow of electrons.

What is an Electric current?

• Electric current is defined as the rate of flow of electric charge, which is the amount of charge flowing through a particular area in a unit of time.
• The direction of the electric current is opposite to the direction of the flow of electrons.

Electric current formula

Electric current refers to the flow of electric charge in a circuit. It is typically denoted by the symbol “I” and is measured in amperes (A).

The formula to calculate electric current in terms of charge and time is as follows:

I = Q / t

Where:

I represent the electric current in amperes (A).

Q represents the electric charge in coulombs (C).

t represents the time in seconds (s).

This formula states that electric current (I) is equal to the electric charge (Q) flowing through a conductor divided by the time (t) it takes for that charge to pass.

The SI unit of electric current is the ampere (A). It is named after the French physicist and mathematician André-Marie Ampère. The ampere is defined as one coulomb of electric charge flowing per second through a conductor.

To use the formula of electric current, you need to know the electric charge passing through the conductor and the time it takes for that charge to flow. By dividing the charge by the time, you can determine the electric current.

For example, if you have a charge of 10 coulombs passing through a conductor in a time span of 5 seconds, you can calculate the electric current as:

I = 10 C / 5 s

I = 2 A

Therefore, the electric current in this scenario would be 2 amperes.

Solved Examples on Electric Current Formula

Example 1: Calculating the electric current

Given:

Electric charge (Q) = 15 coulombs

Time (t) = 5 seconds

To find: Electric current (I)

Solution:

Using the formula for electric current: I = Q / t

Substituting the given values:

I = 15 C / 5 s

I = 3 A

Therefore, the electric current flowing through the circuit is 3 amperes.

Example 2: Calculating the charge flowing in a circuit

Given:

Electric current (I) = 2 amperes

Time (t) = 10 seconds

To find: Electric charge (Q)

Solution:

Using the formula for electric charge: Q = I x t

Substituting the given values:

Q = 2 A x 10 s

Q = 20 C

Therefore, the charge flowing through the circuit during this time is 20 coulombs.

Example 3: Determining the time taken for a specific charge to flow

Given:

Electric current (I) = 0.5 amperes

Electric charge (Q) = 3 coulombs

To find: Time (t)

Solution:

Using the formula for time: t = Q / I

Substituting the given values:

t = 3 C / 0.5 A

t = 6 s

Therefore, it takes 6 seconds for a charge of 3 coulombs to flow through the circuit.

Frequently Asked Questions on Electric Current Formula

What is electric current?

Electric current is the flow of electric charge through a conductor. It is the rate at which charge passes a given point in a circuit and is measured in amperes (A).

How is electric current measured?

Electric current is measured using a device called an ammeter. The ammeter is connected in series with the circuit and provides a direct measurement of the current flowing through the circuit.

What is the difference between direct current (DC) and alternating current (AC)?

Direct current (DC) flows in one direction, maintaining a constant polarity. Alternating current (AC) periodically changes direction, reversing its polarity. DC is commonly used in batteries and electronic devices, while AC is used for power transmission in homes and buildings.

What is the relationship between voltage and electric current?

Voltage (V) and electric current (I) are related through Ohm's law. 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. The formula is I = V / R, where I is the current, V is the voltage, and R is the resistance.

What is the effect of increasing the resistance on electric current?

Increasing the resistance in a circuit reduces the electric current flowing through it, as per Ohm's law. The relationship is inversely proportional. Therefore, a higher resistance results in a lower current for a given voltage.

Is electric current harmful to humans?

Electric current can be harmful to humans depending on its magnitude and path through the body. High currents can cause electric shocks, burns, or even fatal injuries. It is important to exercise caution and follow electrical safety guidelines to prevent accidents.

What is the difference between electric current and electric power?

Electric current (I) is the flow of charge, while electric power (P) is the rate at which electrical energy is consumed or delivered in a circuit. Power is the product of current and voltage, given by the formula P = I x V. It is measured in watts (W).

Can electric current flow in an open circuit?

No, electric current cannot flow in an open circuit because there is no closed path for the charge to follow. In order for current to flow, there must be a continuous conducting path, such as a closed loop.