Moving Charges and Magnetism

Introduction

• Today's topic: Moving Charges and Magnetism
• All concepts, formulas, shortcuts, and previous years' NEET and AIPMT questions on moving charges and magnetism
• Study in seven sections:
  1. Algebraic Derivations
  2. Important Formulas
  3. Practice Questions
  4. Units and Dimensions
  5. Application of Circular Motion
  6. Interrelation of Electromagnetic Fields
  7. Objective and Advanced Questions

Main Analysis

• Biot-Savart Law:

  • Magnetic field due to a current-carrying element is given by the formula:

    dB = (μ₀ / 4π) × (I dl sinθ / r²)

  • Simplification through an elemental charge holder

• Finite Current-Carrying Wire:

  • Finite wire
  • Infinite wire
  • Circular coil
  • Semi-infinite wire
  • Solving questions through difficult concepts
  • Detailed theory and past years' questions

Analysis under Circular Motion

• Motion of charged particles in circular motion and strategy
• Application of velocity variable in the movement of charged particles
• Examples of electrons and protons
• Highly essential questions and their answers

Torque and Current

• Torque formula on a current-carrying wire: τ = μ₀ (IA sinθ)
• Important questions on geometrical forms
• Solved examples and necessary solutions

Other Important Topics

• Galvanometer: Introduction and Theory
• Types of galvanometers
• Important characteristics: Resistance, Sensitivity, etc.
• Formulae: G = (number of turns) x (area) x (couple per unit twist)
• Example questions: Calculation-based problems and concept clarity

Other Brief Topics

• Magnetic Dipole Moment
• Bar Magnet
• Unstable and Stable Equilibrium
• F =
• Analysis of Torque and Potential Energy
• Practicals and comprehensive underlying theory

Important FAQs

1. How to increase the sensitivity of a circular galvanometer?

   • More turns
   • Increase core area
   • Precise magnetics

2. Which variables affect the force on a current-carrying wire in a magnetic field?

   • Value of current
   • Magnetic field strength
   • Velocity and direction
   • Angle θ between v and B

3. Question Framing: Velocity of Electrons Engaged

• Value transitional and velocity