Physics Investigatory Project for Class 12

Project Overview

• Student Name: Shivam Patel
• School: Gujarat Public School, Vadodara
• Class: 12th
• Topic: Coulomb's Law
• Objective: Estimate the charge induced on two identical styrofoam balls suspended in a vertical plane using Coulomb's Law.

Key Components of the Project

Introduction

• Focus on using Coulomb's Law to study electric charges.
• Utilizes styrofoam balls to demonstrate electrostatic forces.

Theory

• Coulomb's Law: Describes the electrostatic force between two stationary electrically charged particles.
  • Mathematical Form: ( F = k \frac{|q_1 q_2|}{r^2} )
    • ( F ): Force between the charges
    • ( k ): Coulomb's constant ( (9 \times 10^9, N \cdot m^2/C^2) )
    • ( q_1, q_2 ): Magnitudes of the charges
    • ( r ): Distance between the charges
  • Like charges repel; opposite charges attract.
• Electrostatics: Study of stationary charges and their forces.
  • Charge is quantized and conserved.
• Charging by Induction: Charging a conductor by bringing it near another charged object without direct contact.

Materials Required

• Identical styrofoam balls
• Physical or electronic balance
• Meter scale
• Teflon thread
• Stand
• Glass or plastic rod
• Silk or wool cloth

Procedure

1. Measure the mass of each styrofoam ball.
2. Suspend the balls using equal-length threads.
3. Rub the glass rod with silk cloth and touch both balls to induce charge.
4. Note the distance between the balls when they become stationary.
5. Repeat the process with additional uncharged balls to observe charge distribution.

Observations and Calculations

• Record the mass, radius, and length of threads for the styrofoam balls.
• Measure the distance between balls when at equilibrium.
• Use Coulomb's Law to calculate the charge on each ball.

Results

• Calculation of the charge on each ball using observed data and Coulomb's Law.

Precautions

• Ensure balls are not touched by any conducting body.
• Properly charge the glass rod with silk for effective results.
• Accurately measure the masses and distances.

Sources of Error

• Potential inaccuracies in measuring the size and mass of balls.
• Error in distance measurement.

Bibliography

• References to sources such as Wikipedia and academia.edu for theoretical background.

Conclusion

This project demonstrates the application of Coulomb's Law in a practical setting and highlights the fundamental principles of electrostatics, allowing for a deeper understanding of electric charges and forces.