NCERT Class 12 Physics Chapter 6 Notes Electromagnetic Induction - Download PDF

NCERT Class 12 Physics Chapter 6 Notes Electromagnetic Induction - Download PDF

Edited By Vishal kumar | Updated on Feb 02, 2024 05:06 PM IST

The chapter on Electromagnetic Induction in NCERT Class 12 Physics explores the fascinating phenomenon in which fluctuating magnetic fields generate electric currents. The accompanying notes provide a concise overview, focusing on key topics such as Magnetic Flux, Faraday's Law of Induction, Lenz's Law, Motional Electromotive Force, Eddy Currents, Inductance, and AC Generators.

This Story also Contains
  1. NCERT Class 12 Physics Chapter 6 Notes-
  2. Faraday’s Law of Electromagnetic Induction
  3. Lenz’s Law:
  4. Motional emf:-
  5. Inductor
  6. AC Generator
  7. Significance of NCERT Class 12 Physics Chapter 6 Notes-
  8. NCERT Class 12 Notes Chapterwise
  9. NCERT Books and Syllabus

These Electromagnetic Induction class 12 notes are an invaluable resource, presenting fundamental equations and concepts required for understanding electromagnetic induction. While derivations are not explicitly covered in the CBSE class 12 physics chapter 6 notes, the extensive coverage ensures a strong foundation in this area of study. Students can use the physics class 12 chapter 6 notes pdf to gain a thorough understanding of electromagnetic phenomena and their practical applications.

Also, students can refer,

NCERT Class 12 Physics Chapter 6 Notes-

  • Electromagnetic Induction (EMI) is the phenomenon of generating current or emf by changing the magnetic flux.
  • Magnetic Flux:- The total number of magnetic lines of force travelling naturally through any surface equals the magnetic flux associated with it. It's a Scalar Quantity

Faraday’s Law of Electromagnetic Induction

The First Law:

When the magnetic flux in a closed-loop or circuit varies, an emf is generated in the loop or circuit that lasts as long as the flux is changing.
Second Law:

The rate of change of magnetic flux in a closed loop or circuit is directly proportional to the induced emf in the closed-loop or circuit.

1644494944253where the negative sign indicates that e is induced in the opposite direction of changing flux.

Lenz’s Law:

The direction of induced emf is determined by Lenz's law.

According to this law, the direction of induced emf in a circuit opposes the change in magnetic flux responsible for its formation. The law of Lenz is based on the idea of energy conservation.

Fleming's right-hand rule:

Fleming's right-hand rule also determines the direction of induced emf or current in a conductor travelling in a magnetic field. According to this rule, if we stretch our right hand's forefinger, central finger, and thumb in mutually perpendicular directions, the forefinger will point in the direction of the field and the thumb will point in the direction of conductor motion, the central finger will point in the direction of induced current or emf.

Lenz's law is used in a variety of situations.


- When a bar magnet's north pole is shifted towards a coil, the current produced in the coil will be anticlockwise.

- When a bar magnet's north pole is moved away from the coil, the current produced in the coil rotates clockwise.

-The direction of current induced in a stationary coil changes as a current-carrying coil is pushed near it.
-The direction of current induced in a stationary coil changes when a current-carrying coil is moved away from it.

Motional emf:-

The generated emf across the ends of a conducting rod of length l moving with a velocity v perpendicular to a uniform magnetic field B is.

1644494946338

Motional emf is the name for this type of emf.

The induced emf if the rod makes an angle with the field direction is.

1644494941815

When a length l conducting rod is rotated perpendicular to a uniform magnetic field B, the induced emf between the rod's ends is

1644494943998

1644494942634

The emf produced between the centre and rim of a conducting solid disc of radius r rotates with a uniform angular velocity w with its plane perpendicular to a uniform magnetic field B.

1644494944721

Eddy currents:

Eddy currents are currents induced in the body of a conductor as a result of a change in magnetic flux associated with the conductor.

  • Lenz's law, often known as Fleming's right-hand rule, determines the direction of eddy currents.

  • Eddy currents form in a metallic conductor in such a way that they oppose the change in magnetic flux associated with it, according to Lenz's law.

  • Eddy currents cannot be completely removed, but they can be reduced by - laminating the core – taking the metallic core in the form of thin laminated sheets that are joined together.

JEE Main Highest Scoring Chapters & Topics
Just Study 40% Syllabus and Score upto 100%
Download EBook

Electromagnetic dampers, induction furnaces, electric brakes, and speedometers all benefit from eddy currents.

Inductor

A device for storing energy in a magnetic field is an inductor. Inductance is the common term for an inductor. In most cases, a coil or solenoid is used as an inductor.

Self-induction: As the current going through a coil or circuit varies, so does the magnetic flux associated with it.

As a result, an emf is generated in the coil or circuit, which opposes the change that is causing it.

Self-induction is the term for this occurrence, and the resulting emf is known as self-induced emf or reverse emf.

-When a current I flows through a coil and phi is the magnetic flux associated with the coil, then, the self-induced emf is given by-

1644494940888.

where L is the coil's coefficient of self-induction.

- Henry (H) is the SI unit of L, and its dimensional formula is ML2T-2A-2

– A circular coil's self-inductance is

1644494945470

where R is the coil's radius and N is the number of turns.

Mutual induction:

As the current going through a coil or circuit varies, so does the magnetic flux coupled to a neighbouring coil or circuit.

As a result, an emf will be induced in the next coil or circuit.

Mutual induction is the term for this occurrence.

The primary coil or circuit is where current changes, while the secondary coil or circuit is where emf is created.

– Assume that at any given time, IP is the current flowing through the primary coil.

If ϕs is the flux connected to the secondary coil, then

1644494942391

where M is the mutual inductance coefficient of the two coils.

1644494946127

is the induced emf in the secondary coil.

- Henry (H) is the SI unit of M and its dimensional formula is ML2T-2A-2.

Coefficient of coupling (K):

The coefficient of coupling of two coils is defined as 1644494944486

where L1 and L2 are the self-inductance coefficients of the two coils, and M is the mutual inductance coefficient of the two coils, respectively.

1644494943180

M is the mutual inductance coefficient of two long co-axial solenoids, each of length l, area of cross-section A, wound on air core, where N1, N2 are the total number of turns of the two solenoids.

Inductance combination – Two self-inductance inductors L1 and L2 are kept so far apart that their mutual inductance is zero.

These are linked together in a series.

L=L1+L2is the equivalent inductance.

– Self-inductance L1 and L2 inductors are coupled in series and have mutual inductance M.

The combination's equivalent inductance is hence

1644494943733

– The plus sign appears when the windings in the two coils are in the same direction, whereas the minus sign appears when the windings are in the opposite direction.

– Inductors L1 and L2 of self-inductors are connected in parallel.

The mutual inductance of the inductors is insignificant because they are so far away.

The equivalent inductance is then

1644494945943

Energy stored in an inductor: The energy stored in an inductor is given by when a current I flows through it.

1644494944972

Magnetic energy is the form of energy stored in an inductor.

AC Generator

  • An electrical generator turns mechanical energy into electrical energy.

  • The phenomenon of electromagnetic induction is used to generate alternating currents (ac).

  • An emf is induced in the coil whenever the magnetic flux changes.

  • A device that converts mechanical energy into electrical energy is known as an AC generator (alternating currents).

  • By altering the magnetic field and area vector, an AC generator can induce an emf or current in a loop.

Principle:-

  • A change in the loop's orientation or effective area causes current to flow through it.

  • Modifying the area vector or changing the induced emf produces induced emf.

  • Fleming's right-hand rule determines the direction of the current.

  • The up and down movement of the loops changes the direction of the current in the circuit.

It based on The phenomenon of electromagnetic induction asserts that whenever the magnetic flux associated with a conductor (or coil) changes, an emf is induced in the coil.

If E is the induced emf in the coil, then

1644494942062

1644494942888

E0=NBAω is the induced EMF's maximum or peak value.

Significance of NCERT Class 12 Physics Chapter 6 Notes-

Comprehensive Revision: The electromagnetic Induction notes class 12 provide a concise summary of the chapter's main topics, making them ideal for quick revision before exams.

Core Themes Coverage: These CBSE class 12 Physics ch 6 notes effectively encapsulate the core themes of the Physics Syllabus for Class 12, ensuring that students understand fundamental concepts such as electromagnetic induction.

Preparation for Competitive Exams: Students preparing for competitive exams such as VITEEE, BITSAT, JEE Main, NEET, and others will benefit from these ch 6 physics class 12 notes because they provide a solid foundation in electromagnetic induction, which is frequently tested in such exams.

Offline Study Material: The availability of Physics class 12 chapter 6 notes pdf format makes offline study easier, allowing students to access and review the material even without an internet connection. This is especially useful for students who prefer to study offline or require materials for use in areas with limited internet access.

NCERT Class 12 Notes Chapterwise

Subject Wise NCERT Exemplar Solutions

Subject Wise NCERT Solutions

NCERT Books and Syllabus

Frequently Asked Questions (FAQs)

1. Are all the main derivations covered in the Class 12 Physics chapter 6 notes?

No, the NCERT notes for Class 12 Physics chapter 6 do not include all of the important derivations. This NCERT note summarises the chapter's important points and equations and can be used to review electromagnetic induction.

2. What do you mean by eddy currents?

Changing magnetic fields can cause current loops in surrounding metal bodies, which are dissipated as heat. Eddy currents are the name for these types of currents.

3. How important is the chapter for the CBSE board exam and how this Class 12 Electromagnetic Induction notes would help?

Students can expect 4 to 6 marks questions from the notes for Class 12 Physics chapter 6  and students can refer to this note for the quick revision purpose which would help them to increase their marks.

4. What is Lenz’s Law?

According to Lenz's law, the polarity of an induced emf tends to produce a current that opposes the change in magnetic flux that caused it.  The opposition is represented by the negative symbol. 

5. What Is an inductor?

Inductor:-A device for storing energy in a magnetic field is an inductor. 

Inductance is the common term for an inductor. 

6. What are Faraday’s Law of Electromagnetic Induction?

Faraday’s Law of Electromagnetic Induction
The First Law 

When the magnetic flux in a closed-loop or circuit varies, an emf is generated in the loop or circuit that lasts as long as the flux is changing.
 Second Law 

The rate of change of magnetic flux in a closed-loop or circuit is directly proportional to the induced emf in the closed-loop or circuit. 

Articles

Upcoming School Exams

Admit Card Date:13 December,2024 - 31 December,2024

Admit Card Date:13 December,2024 - 06 January,2025

Application Date:18 December,2024 - 10 January,2025

Application Date:18 December,2024 - 10 January,2025

Late Fee Application Date:21 December,2024 - 31 December,2024

View All School Exams
Get answers from students and experts

A block of mass 0.50 kg is moving with a speed of 2.00 ms-1 on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is

Option 1)

0.34\; J

Option 2)

0.16\; J

Option 3)

1.00\; J

Option 4)

0.67\; J

A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1 m 1000 times.  Assume that the potential energy lost each time he lowers the mass is dissipated.  How much fat will he use up considering the work done only when the weight is lifted up ?  Fat supplies 3.8×107 J of energy per kg which is converted to mechanical energy with a 20% efficiency rate.  Take g = 9.8 ms−2 :

Option 1)

2.45×10−3 kg

Option 2)

 6.45×10−3 kg

Option 3)

 9.89×10−3 kg

Option 4)

12.89×10−3 kg

 

An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range

Option 1)

2,000 \; J - 5,000\; J

Option 2)

200 \, \, J - 500 \, \, J

Option 3)

2\times 10^{5}J-3\times 10^{5}J

Option 4)

20,000 \, \, J - 50,000 \, \, J

A particle is projected at 600   to the horizontal with a kinetic energy K. The kinetic energy at the highest point

Option 1)

K/2\,

Option 2)

\; K\;

Option 3)

zero\;

Option 4)

K/4

In the reaction,

2Al_{(s)}+6HCL_{(aq)}\rightarrow 2Al^{3+}\, _{(aq)}+6Cl^{-}\, _{(aq)}+3H_{2(g)}

Option 1)

11.2\, L\, H_{2(g)}  at STP  is produced for every mole HCL_{(aq)}  consumed

Option 2)

6L\, HCl_{(aq)}  is consumed for ever 3L\, H_{2(g)}      produced

Option 3)

33.6 L\, H_{2(g)} is produced regardless of temperature and pressure for every mole Al that reacts

Option 4)

67.2\, L\, H_{2(g)} at STP is produced for every mole Al that reacts .

How many moles of magnesium phosphate, Mg_{3}(PO_{4})_{2} will contain 0.25 mole of oxygen atoms?

Option 1)

0.02

Option 2)

3.125 × 10-2

Option 3)

1.25 × 10-2

Option 4)

2.5 × 10-2

If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will

Option 1)

decrease twice

Option 2)

increase two fold

Option 3)

remain unchanged

Option 4)

be a function of the molecular mass of the substance.

With increase of temperature, which of these changes?

Option 1)

Molality

Option 2)

Weight fraction of solute

Option 3)

Fraction of solute present in water

Option 4)

Mole fraction.

Number of atoms in 558.5 gram Fe (at. wt.of Fe = 55.85 g mol-1) is

Option 1)

twice that in 60 g carbon

Option 2)

6.023 × 1022

Option 3)

half that in 8 g He

Option 4)

558.5 × 6.023 × 1023

A pulley of radius 2 m is rotated about its axis by a force F = (20t - 5t2) newton (where t is measured in seconds) applied tangentially. If the moment of inertia of the pulley about its axis of rotation is 10 kg m2 , the number of rotations made by the pulley before its direction of motion if reversed, is

Option 1)

less than 3

Option 2)

more than 3 but less than 6

Option 3)

more than 6 but less than 9

Option 4)

more than 9

Back to top