Introduction

Have you ever brought a charged balloon close to your hair and watched your hair stand up?
Or seen tiny paper pieces jump toward a plastic scale after rubbing it on your clothes?

These effects happen even without touching.
The mysterious force behind this is the Electric Field.

In this article, we will understand electric fields through stories, real-life analogies, diagrams, and Class 12 exam-ready definitions.

Electric Field — The Invisible Influence Around a Charge

Imagine a person wearing strong perfume in a room.
Even if you are sitting far away, after a while you feel their presence through the smell.

A charged particle behaves the same way.

A charge creates an invisible influence in the space around it.
Any other charge entering this region will feel a force — either attraction or repulsion.

This invisible region is called the electric field.

Definition of Electric Field

Electric field at a point is the force experienced by a unit positive test charge placed at that point.

Mathematically,

[
\vec{E} = \frac{\vec{F}}{q}
]

Where:

• E = Electric Field (N/C or V/m)
• F = Force on the test charge
• q = Magnitude of test charge

Imagine Mr. Positive, a friendly person who keeps pushing others away.
And Mr. Negative, who always pulls people close.

Both of them walk into a big empty hall.

Even if they stand silently, each of them creates a kind of aura around themselves — a zone where their personality affects others.

• If someone enters Mr. Positive’s area → they feel a push.
• If someone enters Mr. Negative’s area → they feel a pull.

This aura is exactly like an electric field.

You don’t see it.
You don’t hear it.
But you definitely feel its effect.

Real-Life Example: Balloon and Wall

Rub a balloon on your hair and press it on a wall.
It sticks even after you leave it.

Why?

The balloon becomes charged and creates an electric field.
This field pulls opposite charges inside the wall, making the balloon stick.

This is electric field in action — simple and real.

Electric Field Lines — The Map of the Field

Electric field lines are imaginary lines that show:

• Direction of the electric field
• Strength of the field

Properties of Electric Field Lines (Class 12 Important)

• They start from positive and end at negative charges.
• They never intersect.
• Closer lines → stronger field
• Lines show the path a positive test charge would take.

These lines help us visualize an invisible phenomenon.

Electric Field Due to a Point Charge

For a single charge (Q):

[
E = \frac{1}{4\pi \epsilon_0}\frac{Q}{r^2}
]

This tells us:

• Field becomes weaker as distance increases.
• Positive charge → field points outward
• Negative charge → field points inward

Electric Field Is a Vector

Electric field has:

• Magnitude (strength)
• Direction

Direction = the direction of force on a positive test charge.

Types of Electric Fields

1. Uniform Electric Field

Strength and direction remain the same at all points.

Example:
Inside a parallel plate capacitor.

2. Non-Uniform Electric Field

Field strength changes from place to place.

Example:
Around a point charge.

Why Electric Field Is Important?

Electric fields are used in:

• Capacitors
• Electric circuits
• Particle accelerators
• CRT televisions
• Photocopiers
• Touch screens
• Electric fencing
• Lightning & thunderstorms

Almost every modern technology depends on electric fields.

Summary

• Electric field = region around a charge where force acts without contact
• Formula: ( E = F/q )
• For point charge: ( E = kQ/r^2 )
• Electric field lines show direction and strength
• Field of +Q = outward
• Field of –Q = inward
• Electric field is a vector

FAQs

Is electric field a force?

No.
Electric field is the property of space around a charge that causes a force.

Can electric field exist without a test charge?

Yes.
Field exists even if no other charge is present.

What is the SI unit of electric field?

Newton per Coulomb (N/C) or Volt per meter (V/m).