Current electricity easy notes, Summaries of Physics

Download Current electricity easy notes and more Summaries Physics in PDF only on Docsity!

Chapter 2 - Current Electricity Class 12 Physics | Quick Revision + Top Questions + Formula Sheet ] CHAPTER 2: CURRENT ELECTRICITY — FULL NOTES (Sellable) “ 1. Electric Current e Electric current is the rate of flow of charge through a conductor. | = \frac{Q}{t} ¢ SI Unit: Ampere (A) ¢ Direction: From positive to negative terminal “~ 2. Drift Velocity e Electrons move randomly, but under electric field they get drift velocity (v,) “ 2. Drift Velocity e Electrons move randomly, but under electric field they get drift velocity (v,) I =nqAvq Where: ¢ n = number of electrons * q =charge e A=area “ 5. Resistivity e Property of material ¢ Unit: Qm «> Temperature effect: ¢ Metals — resistance increases ¢ Semiconductors — decreases “~~ 6. Combination of Resistors Series: R=R,+ Ro+ Rp Parallel: “ 7. Electric Power P=VI=PR= e Unit: Watt “ 8. Kirchhoff's Laws Junction Law: ¢ Total current entering = leaving Loop Law: e Sum of potential differences = 0 “ 11. Potentiometer e Measures EMF accurately * More precise than voltmeter @ Exam Booster Important Points: e Ohm's law only for ohmic conductors ¢ Always check units