PHY2_11_12_Q3_0302_FD

Unit 3: Electric Potential

Lesson 3.2: Electric Potential and Potential Difference

Contents

• Introduction

• Learning Objectives

• Warm Up

• Learn about It!

• Electric Potential

• Potential Difference

• Charge and Electric Potential

• Applications of Electric Potential Difference in Circuitry

• Key Points

• Key Formula

• Check Your Understanding

• Challenge Yourself

• Bibliography

• Key to Try It!

Introduction

• Circuitry visualized as energy conversion systems.

• In electric circuits, chemical energy from a battery works on charges by moving them from low to high potential terminals.

• Energy transforms from chemical to electrical and then into other forms (heat, light) when charges move in the external circuit.

Learning Objectives

• Differentiate electric potential and potential difference.

• Explain relationships between charges, electric fields, and electric potential.

• Calculate electric potential in relation to unit charge.

• Identify applications of electric potential in circuitry.

• Understand the concept of work, potential energy, and electric fields in relation to electric potential.

Warm Up: Electric Field and Potential Simulator

• Visualize electric potential maps using the electric field and potential simulator.

• Materials Needed: Electric field simulator, worksheet.

• Set simulator to "two unlike charges" to observe results.

Electric Potential

• Definition: Electric potential (also called potential) is the potential energy per unit charge (U/q).

• SI Unit: Volt (V), equivalent to joule per coulomb (J/C).

• Key Relationship:

  • V = k * q / r, where:

    • V = potential

    • k = Coulomb's constant

    • q = charge

    • r = radius

• Instruments for measuring potential difference: Voltmeters.

Potential Difference

• Defined as the difference in electric potential between two points (Va and Vb).

• Mathematically expressed as:

  • Vab = Va - Vb

• Voltage indicates how much work is done to move a unit charge from one point to another.

• The potential energy increases as a positive charge moves from the negative to the positive terminal of a battery (loss converts to other energy forms in the circuit).

Charge and Electric Potential

• As a charged particle moves within the electric field, its potential energy (UE) decreases.

• Positive Charges:

  • Electric potential is high near the charge and decreases with distance.

• Negative Charges:

  • The electric potential behaves inversely compared to positive charges.

Applications of Electric Potential Difference in Circuitry

• Voltage indicates energy gain/loss during the movement of charges.

• A battery with voltage (e.g., 20 volts) signifies the gain of energy as charges move from the negative terminal to the positive terminal.

Key Points

• Electric potential = potential energy per unit of charge.

• SI Unit: 1 Volt = 1 Joule/Coulomb.

• Electric potential difference is indicative of work done in moving charges between two points.

• The electric field flows from regions of high to low potential.

Key Formula

• Electric Potential:

  • V = k * q / r

Check Your Understanding

• Statements validation: true or false based on electric potential concepts.

Challenge Yourself

• Series of questions relating electric potential changes to kinetic energy movements within electric fields.

• Application scenarios presented with conceptual analysis.