Electrostatic Potential

Electricity is all around us — from the lights in our homes to the devices we use every day. But have you ever wondered how electric charges create forces, or how energy is stored in electric fields? To understand these things, we need to learn about a very important concept in physics: Electrostatic Potential.

Before diving into electrostatic potential, let’s recall that electric charges can either attract or repel each other. Positive and negative charges pull toward each other, while like charges push away. These forces act at a distance, meaning they don’t need to be touching to interact. This interaction happens through something called an electric field. Now, imagine if you had to move a tiny test charge inside that electric field — how much effort or work would it take? That’s where electrostatic potential comes in.

So, what is electrostatic potential? In simple words, electrostatic potential at a point is the amount of work needed to bring a unit positive charge from a faraway place (usually infinity) to that point in an electric field, without accelerating it. It helps us understand how much energy a charge has at a particular location in an electric field.

You can think of it like climbing a hill. If you're at the bottom, you have less potential energy. As you go up, you need to work against gravity, and your potential energy increases. Similarly, moving a charge in an electric field requires work, and this work gets stored as electrostatic potential energy. The higher the potential at a point, the more energy the charge would have at that location.

Do Check: Types of Rocks

Electrostatic potential is a scalar quantity, meaning it has only magnitude and no direction. Its unit is the volt (V), named after the scientist Alessandro Volta. Understanding electrostatic potential is important not only in physics but also in real-life applications like designing electric circuits, batteries, capacitors, and electronic devices.

In Class 12 physics and competitive exams like NEET and JEE, this topic is part of the chapter Electrostatic Potential and Capacitance. It is closely linked with other important concepts like electric fields, electric potential energy, and capacitors.

In the next sections, we will explore the formulas, applications, and derivations related to electrostatic potential in a very easy-to-understand manner.

What is Electrostatic Potential?

Electrostatic potential at a point is the amount of work done to bring a unit positive charge from infinity to that point in an electric field.

Definition: It is the electric potential energy per unit charge.

Formula for Electrostatic Potential

V = W / q

• V = Electrostatic potential (volts)
• W = Work done (joules)
• q = Charge (coulombs)

Electrostatic Potential Due to a Point Charge

V = (1 / 4πε₀) * (Q / r)

Electrostatic Potential Energy

Electrostatic potential energy is the energy stored due to the position of charges.

Formula: U = (1 / 4πε₀) * (q₁q₂ / r)

Do Check: Enthalpy

Dimension of Electrostatic Potential

The dimension of electrostatic potential is [ML²T^-3I^-1].

Relation Between Electrostatic Potential and Capacitance

Capacitance (C): C = Q / V

Applications in Daily Life

• Used in capacitors in electronics
• Helps explain lightning and electric shocks
• Important in designing circuits and filters

Electrostatic Potential in Conductors

In conductors, the electrostatic potential is the same throughout, and no electric field exists inside in electrostatic equilibrium. This leads to electrostatic shielding.

Do Check: Zener Diode

Electrostatic Potential and Capacitance – NCERT Solutions and Notes

Use electrostatic potential and capacitance NCERT solutions and notes for exam preparation. These include solved problems and derivations. You can also access the electrostatic potential and capacitance NCERT PDF or notes PDF for quick revision.

Numerical Example

Q: Find the electrostatic potential energy between two charges of +3μC and -3μC placed 0.1 m apart.

Solution: U = 9 x 10⁹ * (3 x 10^-6 * -3 x 10^-6) / 0.1 = -0.81 J

Do Check: Weathering

Conclusion

We explored how to define electrostatic potential, learned about electrostatic potential energy and its formula, examined the dimension of electrostatic potential, and connected everything with capacitance. With the help of electrostatic potential and capacitance NCERT solutions and downloadable notes PDF, you can revise efficiently for Class 12 exams or competitive exams like NEET and JEE.