NCERT Solutions for Class 12 Physics, Chapter 7 - Alternating Current

In this chapter, you’ll study about Alternating Current and its applications. Till now, you studied what direct current (DC) is all about, how it is generated, its applications and more. So, what is Alternating current (AC)?

Alternating Current is an electric current that reverses its direction regularly as opposed to direct current that flows in one direction itself. AC is generated using a device known as an alternator. Alternating current has wide applications in today’s modern world and it is used in households and commercial buildings extensively. You mostly use alternating current while plugging the electrical appliances such as televisions, fans, toasters, dishwashers, refrigerators to the switchboard. Alternating current is used mainly for production and transmission of electricity and has several advantages over direct current such as lower risks of fire explosion, cheaper rates during long-distance transmission, easy conversion of high voltage and low current into low voltage and high current and more.  Alternating current is also widely used in converting electric energy into mechanical energy.

Thus, an in-depth study of Class 12 Physics NCERT Solutions Chapter 7 will give you a good understanding of significant aspects of Alternating Current.

Let’s take a look at topics and sub-topics of Class 12 Physics Chapter 7 – Alternating Current

7.1 Introduction

7.2 AC Voltage Applied to a Resistor

7.3 Representation of AC Current and Voltage by Rotating Vectors – Phasors

7.4 AC Voltage Applied to an Inductor

7.5 AC Voltage Applied to a Capacitor

7.6 AC Voltage Applied to a Series LCR Circuit

7.6.1 Phasor-diagram solution

7.6.2 Analytical solution

7.6.3 Resonance

7.7 Power in AC Circuit: The Power Factor

7.8 LC Oscillations

7.9 Transformers

In Class 12 Physics Chapter 7, you will learn – 

Section 7.2 – In this section, you will study about AC voltage applied to a resistor along with illustrations and related equations.

Section 7.3 – In this section, you’ll acquire knowledge about the representation of AC Current and Voltage by Rotating Vectors such as Phasors along with the diagrammatic representation of the same.

Section 7.4 – In this section, you’ll learn about AC Voltage Applied to an Inductor. You’ll also come across illustrations showing an AC source connected to an inductor, and Magnetisation and demagnetisation of an inductor.

Section 7.5 – In this section, you will study about AC Voltage Applied to a Capacitor, Charging and discharging of a capacitor along with related illustrations.

Section 7.6 – In this section, you will learn about AC Voltage Applied to a Series LCR Circuit, Phasor-diagram solution, Analytical solution and what Resonance is all about, etc.

Section 7.7 – In this section, you’ll learn about power in AC Circuit, known as ‘The Power Factor’. You’ll also study some cases related to power factor such as Resistive circuit, Purely inductive or capacitive circuit, LCR series circuit and Power dissipated at resonance in LCR circuit.

Section 7.8 – In this section, you will study about LC Oscillations, equations related to LC Oscillations, a diagrammatical representation of LC Oscillations and analogies between mechanical and electrical quantities.

Section 7.9 – In this section, you will learn about transformers, how transformers work, uses of transformers in day to day lives, illustrations showing two arrangements for winding of primary and secondary coil in a transformer, and reasons why small energy losses occur in actual transformers.

In this chapter, you are provided with several examples with their solutions for clear understanding about Alternating Current. To know more about NCERT Solutions for Class 12 Physics Chapter 7, you should explore the exercises mentioned in this chapter. You can also download the NCERT Solutions for Class 12 Physics Chapter 7 PDF, solved by our science experts.