Page 1: Introduction

Electricity: flow of electric charge.

Charge: property (positive/negative), conserved.

Conductors and insulators.

Page 2: Electric Current

Unit: ampere (A)

1 A = 1 C/s

Page 3: Potential Difference

Unit: volt (V)

1 V = 1 J/C

Page 4: Ohm’s Law

At constant temperature.

Graph V vs I straight line through origin.

Page 5: Resistance

ρ = resistivity

Factors: length↑ R↑, area↑ R↓, temperature↑ R↑ (metals)

Page 6: Series Combination

Current same, voltage divides.

Page 7: Parallel Combination

Voltage same, current divides.

Page 8: Heating Effect

Electric fuse, heater, bulb.

Page 9: Electric Power

Unit: watt (W)

Commercial: kWh (unit)

Page 10: Key Formulas Summary

• I = Q/t
• V = IR
• R = ρl/A
• Series/Parallel
• P = VI

Page 11: Practice Questions - Easy (1-10)

1. Unit of current.
2. Ohm’s law statement.
3. 1 kWh = ? J
4. Resistance in series.
5. Power formula.
6. Resistivity unit.
7. Heating effect formula.
8. Parallel current.
9. 1 volt definition.
10. Fuse principle.

Page 12: Practice Questions - Medium (11-20)

11. Current if 10 C in 5 s.
12. Resistance if V=12, I=2 A.
13. Power 100 W bulb at 220 V current.
14. Equivalent R two 4 Ω series.
15. Two 6 Ω parallel R_eq.
16. Heat if I=3 A, R=10 Ω, t=10 s.
17. Cost if 2 kW 5 hours at ₹5/unit.
18. Resistivity if R=20 Ω, l=1 m, A=0.1 mm².
19. Three 2 Ω parallel R_eq.
20. Work done moving 5 C at 10 V.

Page 13: Practice Questions - Hard (21-30)

21. Mixed series parallel R_eq.
22. Current division in parallel.
23. Power comparison same V different R.
24. Board level combination numerical.
25. Energy consumption multiple appliances.
26. Resistance wire length change.
27. Heating comparison different currents.
28. Fuse rating calculation.
29. Resistivity temperature effect.
30. Real-life circuit problem.

Page 14: Formula Table

All important formulas.

Page 15: Common Mistakes

• Wrong series/parallel formula
• Forgetting square in power
• Unit conversion kWh
• Sign error in current
• Missing time in heat

Page 16: Previous Year Questions

Combination, power, heating, numerical.

Page 17: Exam Tips

• Draw circuit diagram
• Write formula first
• Show calculation steps
• Check units
• Practice combination circuits

Page 18: Quick Revision Sheet

All formulas, units.

Page 19: Final Motivation

Chapter 12 complete! Electricity is numerical-heavy.

Master combination and power.

Class 10 Science unstoppable 🦖

Page 20: Extra Numericals

More solved problems.

Page 21: Combination Circuits

Step-by-step.

Page 22: Power Calculations

Different forms.

Page 23: Board Pattern

Common numericals.

Page 24: Extra Practice

More questions.

Page 25: Resistivity Factors

Material, temperature.

Page 26: Domestic Circuit

Fuse, earthing.