Electromagnetic Induction — Class 12 Physics NCERT Solutions (Free)
Free step-by-step NCERT solutions for Class 12 Physics chapter "Electromagnetic Induction" — 7 important questions with detailed answers for CBSE board exam preparation.
TL;DR: Free step-by-step NCERT solutions for Class 12 Physics chapter "Electromagnetic Induction" — 7 important questions with detailed answers for CBSE boar…
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Key Questions Covered:
- State Faraday's law of electromagnetic induction. Write mathematical expression.
- A square loop of side 10 cm is placed in magnetic field 0.5 T. If field decre…
- Define self-inductance (L). Derive expression for self-inductance of solenoid.
- + 4 more questions in the full chapter
Solutions Summary:
| Question | Status |
|---|---|
| State Faraday's law of electromagnetic induction. Write m… | ✓ Solved |
| A square loop of side 10 cm is placed in magnetic field 0… | ✓ Solved |
| Define self-inductance (L). Derive expression for self-in… | ✓ Solved |
Showing 3 of 7 questions
Q1: State Faraday's law of electromagnetic induction. Write mathematical expression.
Faraday's Law of Electromagnetic Induction: Rate of change of magnetic flux through a circuit induces emf in the circuit.
Mathematical Expression:
ε = -dΦ_B/dt
where ε = induced emf (volts)
Φ_B = magnetic flux (Weber, Wb)
t = time (seconds)
Alternatively, for N turns:
ε = -N(dΦ_B/dt)
Integral fo...
Q2: A square loop of side 10 cm is placed in magnetic field 0.5 T. If field decreases to 0.2 T in 0.1 s, find induced emf.
Given: Side of square loop = 10 cm = 0.1 m
Initial magnetic field B₁ = 0.5 T
Final magnetic field B₂ = 0.2 T
Time interval Δt = 0.1 s
Field perpendicular to loop (θ = 0°)
Area of loop:
A = side² = (0.1)² = 0.01 m²
Initial flux:
Φ₁ = B₁A cos 0° = 0.5 × 0.01 = 0.005 Wb
Final flux:
Φ₂ = B₂A cos 0° =...
Q3: Define self-inductance (L). Derive expression for self-inductance of solenoid.
Self-Inductance (L): Property of coil to oppose change in its own current.
Definition: L = |ε|/|dI/dt| = Φ_B/I
where ε = induced emf
dI/dt = rate of change of current
Φ_B = magnetic flux through coil
I = current in coil
SI Unit: Henry (H) = Wb/A = V⋅s/A
Smaller units: mH (millihenry), μH (microh...
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