Moving Charges and Magnetism
🔹 Magnetic Force (Lorentz Force)
F = q(v × B)
Angle θ hone par: F = qvB sinθ
🔹 Force on Current Carrying Wire
F = I(L × B)
🔹 Motion in Magnetic Field
Radius of circular path:
r = mv / (qB)
Time period:
T = 2πm / (qB)
🔹 Biot-Savart Law
dB = (μ₀ / 4π) * (Idl × r̂) / r²
🔹 Magnetic Field of Straight Wire
B = μ₀I / (2πr)
🔹 Ampere’s Law
∮B·dl = μ₀I
🔹 Force Between Two Wires
F/L = μ₀I₁I₂ / (2πd)
🔹 Moving Coil Galvanometer
τ = nBIA
🔥 Important PYQs
Q1. Electron enters perpendicular to magnetic field. What is its path?
👉 Answer: Circular
Q2. Two parallel wires carry current in same direction. Force between them?
👉 Answer: Attractive
Q3. Radius increases when velocity increases. True or False?
👉 Answer: True (r ∝ v)
Q4. What happens if charge is negative?
👉 Direction reverses
📚 Quick Tips
- Right hand rule yaad rakhna
- Formula ratne se zyada application samajh
- PYQs repeat hote hain is chapter me
🔗 Navigation
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