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All About Current Electricity | Formulas, Subtopics,Numericals

by maitrisharma511
all about current electricity

Electricity is the movement of charge in a conductor from the anode to the cathode. Electricity has many uses in our daily lives. It is an essential tool for powering electrical equipment in our homes and offices. Therefore, one can say that the flow of electric charge is accumulating the current that we call electricity. This blog will discuss what electricity is, the use of electricity, different types of electricity formulas, and their uses.

What is current electricity?

We can define the current electricity as the flow of electrons from one circuit section to another. Current is generated only by the flow of electric charge. Both positive and negative charges can flow in the forward and reverse directions. Conductors are a very good medium of electricity. Also, when an electric field is applied, a force is applied to the electric charge. The current is identical for all cross-sections of conductors with non-uniform cross-sections.

Types of Current Electricity

There are following two types of electricity:

  • Direct Current
  • Alternating Current

Direct Current

The Current Electricity that remains in the same direction is called direct current. Direct current is defined by the constant flow of electrons from the high electron density region to the low electron density region. The use of direct current is in many appliances and applications that use batteries.

Application of Direct Current

  • Batteries: Non-rechargeable and Rechargeable, both kinds of batteries only supply Direct Current (DC). 
  • Electronic types of equipment: 

All the major electronic equipment like cellphones, computers, radios, and other electronic appliances use DC to power their electronic circuits.

  • Solar Panels:

The electricity turned out by the solar panel is mainly DC. However, we use the inverter to convert the direct current produced by solar panels into alternating current (AC),

Alternating Current

The current that constantly changes the direction of charge flow in both directions is called alternating current (AC). Interactivity is caused by a sinusoidal changing current and voltage reversal direction, producing periodic back-and-forth movements concerning the current. The supply of alternating current into the sockets of our homes and industries.

Application of Alternating Current

  • The main use of alternating current is in power distribution. The main advantage of AC is that one can easily convert it to other voltage by using a simple transformer.
  • Alternating current is also a more common electric current when powering an electric motor, which is a device that converts electrical energy into mechanical energy. Home appliances that we use daily rely on alternating currents, such as refrigerators, dishwashers, waste disposal, toasters, etc.

Some Important Electricity Terminology and Formula

Below we are sharing the current electricity all formulas.

  • Current

Electric current is a flow of charge carriers, mostly electrons or electron-deficient atoms. The common symbol for electricity is capital I. The standard unit is amperes, represented by A.

Current Formula 

I = Qt


I = Current

Q = Charge

T = Time

  • Voltage

The potential difference between the two locations can be expressed as a voltage. Voltage is the “pressure” that carries electricity. In physics, a voltage can be calculated using Ohm’s law. Ohm’s law shows that voltage is equal to the product of resistance and current.

Voltage Formula

V = QC  


V = Voltage

Q = Charge

C = Capacitance

  • Resistance

Resistance is a measure of opposition to the current flow in an electrical circuit. Resistance is measured in ohms and is represented by omega (Ω). Ohm is called after Georg Simon Ohm (1784-1854), a German physicist who studied the link between voltage, current, and resistance.

Resistance Formula

R = iA


R = Resistance

= Resistivity

i = Current

A = Cross Sectional Area

  • Current Formula

I = VR

I = Current

V = Voltage

R = Resistance

  • Electric Power

In physics, electric power measures the transfer coefficient of electrical energy through an electrical circuit per unit of time. Indicated by P and measured using SI units of power. It is watts or 1 joule per second. Electrical energy is usually supplied by batteries and generated by a generator.

P =V I 


P = Electric Power

V = Voltage

I = Current

  • Conductivity

When a potential difference is applied between two points in the material, the property of the material that allows electrons (or charged particles) to flow between those points is called the wire’s conductivity. SI base unit of conductivity: Siemens per meter.

= 1

= Conductivity

= Resistivity

Q.1: Find out the amount of current flowing through the electric heater having a voltage of 220 V and resistance is 100Ω.


As given in the problem:

Resistance R = 100Ω

Voltage V = 220 V

The current formula is given below:

I = V / R

I = 220 / 100

I = 2.2 A

 amount of current flow is 2.2 A.

Hope This article will help you to understand current electricity for more you can visit PW.live. At Physics Wallah they provide the best quality study material such as NCERT Solutions for all Classes, Sample Papers, Science Formula Sheet, Previous Year Question Papers and many more.

maitrisharma is the author of this article

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