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Chapter 23 of 32
Formula Sheet

Alternating Current

ICSE · Class 12 · Physics

All formulas from Alternating Current in ICSE Class 12 Physics. Key equations, constants, and identities for board exam preparation.

70 questions37 flashcards5 concepts

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A graph showing the linear relationship between inductive reactance (X_L) and frequency (f or ω), demonstrating that X_L increases proportionally with frequency.
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19 Formulas · 4 Sections

Formulas

1) Core Ideas and Waveforms

I = I0 sin ωt

V = V0 sin ωt

V0 = NBAω

T = 2π/ω

f = ω/(2π) = 1/T

2) Mean Value and RMS Value

Im = (2/π)I0 = 0.637 I0

Irms = I0/√2 = 0.707 I0

Vrms = V0/√2 = 0.707 V0

Im = 0

Irms for i = a + b sin ωt = √(a^2 + b^2/2)

3) Phasors and Phase Relations

tan φ = (XL − XC)/R = (ωL − 1/ωC)/R

In pure resistor, current is in phase with voltage

In pure inductor, current lags voltage by 90°

In pure capacitor, current leads voltage by 90°

4) Reactance, Impedance and Resonance

XL = ωL = 2πfL

XC = 1/ωC = 1/(2πfC)

Z = √(R^2 + (XL − XC)^2)

f0 = (1/2π)√(1/LC)

Q = (1/R)√(L/C)

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Frequently Asked Questions

What are the important topics in Alternating Current for ICSE Class 12 Physics?
Alternating Current covers several key topics that are frequently asked in ICSE Class 12 board exams. Focus on the core concepts listed on this page and practise related questions to build confidence.
How to score full marks in Alternating Current — ICSE Class 12 Physics?
Understand the core concepts first, then work through the 70 practice questions available for this chapter. Revise formulas and definitions regularly, and use flashcards for quick recall before the exam.

Sources & Official References

Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.

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