Video Lectures
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Chapter Notes
Download our free, comprehensive PDF notes for Alternating Current. These notes are perfectly aligned with the latest NCERT syllabus and include detailed explanations of all crucial topics.
Key Concepts
- AC generator: principle and working
- AC Values: RMS and peak values of AC
- Circuits: Impedance in R, L, C circuits; phasors
- Resonance: Series LCR resonance circuit
- Power: Power in AC circuit; power factor
Important Formulas
RMS Values: V_rms = V₀/√2; I_rms = I₀/√2
Impedance: Z = √(R² + (X_L − X_C)²)
Reactance: X_L = ωL; X_C = 1/ωC
Resonance: ω₀ = 1/√(LC)
Power: Power factor = cosφ = R/Z; P = V_rms I_rms cosφ
Solved Numerical Examples
Example 1
Question: LCR series circuit: L=10mH, C=100μF, R=20Ω. Find Resonant frequency.
Solution: f₀ = 1/(2π√LC) = 1/(2π√(10⁻²×10⁻⁴)) = 159 Hz
Example 2
Question: Power factor of circuit with R=30Ω, X_L=40Ω?
Solution: Z=50Ω, cosφ = R/Z = 30/50 = 0.6
DPP (Daily Practice Problems)
Practice makes perfect. Test your understanding with our Daily Practice Problems designed specifically for Alternating Current.
MCQs
Prepare for objective-type questions with our curated list of Multiple Choice Questions. Practice MCQs here.
Previous Year Questions (PYQs)
Analyze the exam pattern and test your readiness with Previous Year Questions from CBSE boards, JEE Main, and NEET. Solve PYQs here.
Common Mistakes to Avoid
- Forgetting to convert units to the standard SI system before calculation.
- Misinterpreting the direction of vector quantities in complex problems.
- Skipping the foundational derivations, which are crucial for conceptual clarity.
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