Magnetic Effects of Current and Magnetism
Magnetic Effects of Current and Magnetism is a high-weightage chapter in JEE Main Physics.
It covers magnetic fields due to moving charges and current-carrying conductors, force on charges,
electromagnetic devices, and magnetic properties of materials. This chapter is highly important
for both conceptual understanding and numerical problem-solving.
Topics Covered
- Magnetic Field and Magnetic Lines of Force
- Biot-Savart Law
- Ampere’s Circuital Law
- Magnetic Field due to Straight Wire
- Magnetic Field due to Circular Loop
- Magnetic Field due to Solenoid and Toroid
- Lorentz Force
- Force on Current-Carrying Conductor
- Force Between Two Parallel Conductors
- Torque on Current Loop
- Moving Coil Galvanometer
- Bar Magnet and Magnetic Dipole
- Earth’s Magnetism
- Dia, Para, and Ferromagnetic Materials
Important Formulas
Lorentz Force:
F = q(v × B)
Force on Current Carrying Conductor:
F = BIL sinθ
Magnetic Field due to Long Straight Wire:
B = μ₀I / 2πr
Magnetic Field at Center of Circular Loop:
B = μ₀I / 2R
Torque on Current Loop:
τ = N B I A sinθ
JEE Main Preparation Tips
- Memorize all magnetic field formulas and applications.
- Practice right-hand thumb and Fleming’s rules.
- Master force and torque-based numerical problems.
- Understand galvanometer conversion concepts.
- Solve previous year JEE Main questions for accuracy and speed.
