eVidyarthi

Main Menu
  • eVidyarthi
  • School
    • Class 6th
      • Maths Class 6
      • Science Class 6
      • Hindi Class 6
      • व्याकरण
      • English Class 6
      • English Grammar
      • Sanskrit Class 6
      • Geography
      • Civics
      • History
    • Class 7th
      • Maths Class 7
      • Science Class 7
      • Hindi Class 7
      • व्याकरण
      • English Class 7
      • English Grammar
      • Sanskrit Class 7
      • Geography
      • Civics
      • History
    • Class 8th
      • Maths Class 8
      • Science Class 8
      • Hindi Class 8
      • व्याकरण
      • English Class 8
      • English Grammar
      • Sanskrit Class 8
      • Geography
      • Civics
      • History
    • Class 9th
      • Maths Class 9
      • Science Class 9
      • Hindi Class 9
      • English Class 9
      • English Grammar
      • व्याकरण
      • Economics Class 9
      • Geography Class 9
      • Civics Class 9
      • History Class 9
    • Class 10th
      • Maths Class 10
      • Science Class 10
      • Hindi Class 10
      • English Class 10
      • English Grammar
      • व्याकरण
      • Economics Class 10
      • History Class 10
      • Civics Class 10
      • Geography Class 10
    • Class 11th
      • Maths Class 11
      • Accounts Class 11
      • English Class 11
      • English Grammar
      • व्याकरण
      • Chemistry Class 11
      • Physics Class 11
      • Biology Class 11
    • Class 12th
      • Maths Class 12
      • Accounts Class 12
      • Chemistry Class 12
      • Physics Class 12
      • Biology Class 12
      • English Class 12
      • English Grammar
      • व्याकरण
    • Close
  • English
    • Basic English Grammar
    • Basic English Speaking
    • English Vocabulary
    • English Idioms & Phrases
    • Personality Enhancement
    • Interview Skills
    • Close
  • Softwares
    • Microsoft Word
    • PhotoShop
    • Excel
    • Illustrator
    • PowerPoint
    • Close
Class 12th Physics || Menu
  • Important
    • Previous Year Papers
    • Sample Papers
    • MCQs
    • Revision Notes
    • Physics Syllabus
    • Physics Book
    • Marking Scheme
    • Weightage
    • Close
  • Electric Charges and Fields
    • Electric Charge
    • Coulomb’s Law
    • Electric Field
    • Electric Flux
    • Electric Dipole
    • Gauss Law
    • Gold Leaf Electroscope
    • Close
  • Electrostatic Potential and Capacitance
    • Electrostatic Potential
    • Equipotential Surfaces
    • Electrostatic Potential Energy
    • Electrostatics of Conductors
    • Capacitors
    • Combination of Capacitors
    • Electrostatics of Dielectrics
    • Close
  • Current Electricity
    • Ohm’s Law
    • Drift of Electrons and Resistivity
    • Combination of Resistors
    • emfs and Internal Resistance
    • Combination of Cells
    • Kirchhoff’s Rules
    • Electrical Appliances
    • Close
  • Moving Charges and Magnetism
    • Magnetic Lorentz Force
    • Motion in Combined E and B Fields
    • Biot Savart Law
    • Ampere’s Law
    • The Solenoid and Toroid
    • Force on Current Carrying Wire
    • Torque on Current Carrying Loop
    • Close
  • Magnetism and Matter
    • Magnetic Field
    • Magnetic Properties
    • Close
  • Electromagnetic Induction
    • Magnetic Flux
    • Faraday’s Laws of Induction
    • Motional emf
    • Eddy Currents
    • Inductance
    • AC Generator
    • Close
  • Alternating Current
    • AC Applied Across Resistor
    • AC Applied Across Capacitor
    • AC Applied Across Inductor
    • AC Applied to LCR in Series
    • Resonance in LCR Circuit
    • Power in AC Circuit
    • Close
  • Electromagnetic Waves
    • Characteristics of EM Waves
    • Electromagnetic Spectrum
    • Close
  • Ray Optics and Optical instruments
    • Reflection by Spherical Mirrors
    • Refraction by Plane Surfaces
    • Total Internal Reflection
    • Refraction by Spherical Surfaces
    • Refraction by Lens
    • Refraction and Dispersion by Prism
    • Optical Instruments
    • Close
  • Wave Optics
    • Coherent and Incoherent Sources
    • Interference of Light
    • Diffraction of Light
    • Polarisation
    • Close
  • Dual Nature of Radiation and Matter
    • Photoelectric Effect
    • Dual Nature of Matter
    • Close
  • Atoms
    • Alpha Particle Scattering
    • Bohr’s Model of Atom
    • Close
  • Nuclei
    • Atomic Nucleus
    • Nuclear Energy
    • Radioactivity
    • Close
  • Semiconductor Electronics
    • Types of Materials
    • PN Diode
    • Applications of PN Diode
    • Transistors
    • Applications of Transistors
    • Logic Gates
    • Close
  • Communication Systems
    • Signals and Transmission Systems
    • Modulation and Detection of Signals
    • Close

Alternating Current Class 12 Chapter 7 Notes

1. Alternating Current (AC) It is the current which varies in both magnitude as well as direction alternatively and periodically.
I = I0 sin ωt or I = I0 cosωt where, I0 = peak value or maximum value of AC.
2. Effective Value or rms Value of AC It is defined as the value of AC over a complete cycle which would generate same amount of heat in a given resistors that is generated by steady current in the same resistor and in the same time during a complete cycle.
alternating-current-cbse-notes-for-class-12-physics-1
The 70.7% of peak value of current gives effective or rms value of AC.
3. Average or Mean Value of AC It is defined as the value of AC which would send same amount of charge through a circuit in half-cycle that is sent by steady current in the same time.
alternating-current-cbse-notes-for-class-12-physics-2
The 63.7% of peak value of AC gives average or mean value of AC.
NOTE: In a complete cycle of AC, the mean value of AC will be zero.
4. Alternating emf or Voltage It is the emf which varies in both magnitude as well as direction alternatively and periodically. The instantaneous alternating emf is given by
alternating-current-cbse-notes-for-class-12-physics-3
Both AC voltage and AC current are represented by diagrams as shown below:
alternating-current-cbse-notes-for-class-12-physics-4
5. Inductive Reactance (XL) The opposing nature of inductor to the flow of current is called Inductive reactance.
alternating-current-cbse-notes-for-class-12-physics-5
6. Capacitive Reactance (Xc) The opposing nature of capacitor to the flow of alternating current is called capacitive reactance.
alternating-current-cbse-notes-for-class-12-physics-6
7. Power In an AC circuit, both emf and current change continuously w.r.t. time, so in circuit, we have to calculate average power in complete cycle (0 –> T).
alternating-current-cbse-notes-for-class-12-physics-7
8. Average power consumption in pure inductive and pure capacitive circuit is equal to zero because
alternating-current-cbse-notes-for-class-12-physics-8
9. Wattless Current The current in an AC circuit when average power consumption in AC circuit is zero, is referred as wattless current or idle current.

Android App

eVidyarthi

Search On eVidyarthi

Evidyarthi on Facebook

Like us on Facebook

Follow Evidyarthi on Youtube

Learn English
Learn English Through हिन्दी
Job Interview Skills
English Grammar
हिंदी व्याकरण - Vyakaran
Mathematics Class 6th
Science Class 6th
हिन्दी Class 6th
Mathematics Class 7th
Science Class 7th
हिन्दी Class 7th
हिन्दी Class 8th
Mathematics Class 8th
Mathematics Class 9th
English Class 9th
Science Class 9th
Mathematics Class 10th
English Class 10th
Mathematics Class XI
Chemistry Class XI
Accountancy Class 11th
Accountancy Class 12th
Mathematics Class 12th
Microsoft Word
Microsoft Excel
Microsoft PowerPoint
Adobe PhotoShop
Adobe Illustrator
Learn German
Learn French
IIT JEE
Privacy Policies, Contact Us
Copyright © 2020 eVidyarthi and its licensors. All Rights Reserved.