DC Pandey Alternating Current Solutions

DC Pandey Electricity and Magnetism Solutions for Chapter 25 ‘Alternating Current’ is a set of answers prepared to provide assistance for CBSE Class 12 board exams along with JEE Physics preparations. The topics in this chapter of DC Pandey Solutions can fetch you full marks if grasped clearly. These topics are an introduction to alternating currents and phasors, current and potential relations, phasor algebra, series L-R, C-R, and L-C-R circuits. You will also learn the physics involved in a Parallel Circuit, Power in an AC circuit, and the choking cell.

There are 100 questions in the exercise solutions of DC Pandey Electricity and Magnetism Solutions for Alternating Current divided into 3 exercises. The exercises cover all the topics comprehensively in a question-answer format and will, therefore help you prepare for your entrance exams well. The questions also cover all the patterns of questions in this chapter such as match the columns, multiple-choice questions with more than one choice correct, subjective questions, true or false, etc. It is advised to practice all the questions using the Instasolv platform as your source of reference.

The expert team of Instasolv has created this set of DC Pandey Alternating Current Solutions for JEE to address the most frequently occurring queries while practising numerical problems. The solutions make full use of diagrams and other interactive methods to clarify all the concepts. Such an approach will not only build a strong foundation but also a robust aptitude for your engineering or physical sciences career ahead. You will be able to amplify your marks significantly with your time at Instasolv.

Important Topics for DC Pandey Electricity and Magnetism Solutions Chapter 25: Alternating Current

Alternating Currents and Phasors

  • A phasor is a vector that is used to represent a sinusoidal signal. When we have more than one sinusoidal signal with the same frequency, different phases, and different amplitude then we can use this phasor diagram to represent the phase difference between these sinusoidal signals.
  • The magnitude of the phasor represents the peak value of the voltage and the current.
  • The term “phasor” can also be applied to impedance or other related complex quantities that are time-independent.

There are three ways of phasor representation in mathematical form:

  • Polar Form: Suppose we have a phasor which has an amplitude of Vm and makes an angle with the horizontal axis. So in the polar form, we can represent it as Vm.

Rectangular Form: In this form, we can represent any phasor as a complex number like A+iB

  • Exponential Form: Here we represent the phasor in the form of as

Current and Potential Relations

Ohm’s law was formulated by Georg Ohm. This law states that if there is a current passing through a conductor between two given points, this current is directly proportional to the potential difference across the two points, introducing the constant of the proportionality termed as the resistance.

Mathematically the ohm’s law can be given as,


Series L-R Circuit

Let an AC of EMF, E be connected to a series combination of a capacitor of pure capacitor C and resistor R.

The source voltage is given by, V= Vo sin ωt  

The potential difference across the resistor is given by, VR = IR

The voltage across Inductance is given by, VL = IXL

The phase difference between VR and VL will be 90 Degrees

The resultant voltage will be V2 = VR2 + VL2

Comparing this with ohms law we get impedance Z

Phase difference will be given by ϕ=tan−1

Current is given by, I = Io sin(ωt−ϕ) 

Where ϕ is the phase difference

Series C-R Circuit


Phase difference will be given by ϕ = tan-1 

Current is given by, I = Iosin(ωt+ϕ)

 Where ϕ is the phase difference

Series L-C-R Circuit


Phase difference,

Current IS = Im sin ωt

Choking Coil

A choke coil is essentially an inductor coil with large inductance and very low resistance. It offers high inductive-reactance, thus high impedance, to AC voltage, and thus limits the current in the AC circuit, without increasing the resistance of the circuit.

Exercise Discussion for DC Pandey Electricity and Magnetism Solutions Chapter 25: Alternating Current

  • Introductory Exercises:
  1. Exercise 25.1 covers the alternating current and phasors in the 2 questions in this exercise.
  2. The exercise questions of 25.2 are based on current and potential relations.
  3. The questions in exercises 25.3 and 25.4 cover the different kinds of series circuits besides containing questions related to the parallel circuit.

AIEEE Corner (Now a part of JEE):

In this exercise, all the important topics in this chapter are covered in a section-wise manner comprising of multiple-choice questions as well as subjective questions. The questions are of both, the beginner and the advanced level in this exercise. You will get to solve questions based on the circuits represented diagrammatically.

  1. JEE Corner:

The questions on the series L-R, C-R, and L-C-R circuits are of vital importance in the Joint Entrance Exams. Therefore, these questions are accordingly covered in this exercise in different formats such as subjective questions, assertion-reasoning problems, and match the column questions. Other topics of this chapter are also covered in this exercise with the help of advanced level questions for a final brush up in your exam preparation 

Why Use DC Pandey Electricity and Magnetism Solutions Chapter 25: Alternating Current by Instasolv?

  • DC Pandey Electricity and Magnetism Alternating Current Solutions for JEE are prepared by the expert faculties at Instasolv. 
  • Therefore, about the quality and accuracy of the answers, you can rely on us unhesitatingly. 
  • The platform at Instasolv is student-friendly and easily accessible. You will get the answers to all your queries proactively while solving the questions.
  • Teaming up with Instasolv will definitely fetch you better marks in Class 12 board exams as well as our solutions ensure complete and rigorous preparation for your exams.