Electromagnetic Induction Notes by Sir Asad Abbas

Important Easy to understand Notes of Physics of class 12th physics chapter 15 notes Electromagnetic Induction written by Professor Mr. Asad Abbas Suib. These notes are very helpful in the preparation of class 12th physics chapter 15 notes for students of the 12th class and these are according to the paper patterns of all Punjab Book Boards.

Summary and Contents:

Topics which are discussed in the notes are given below:

Important class 12th physics chapter 15 for Intermediate part-II students.
Definition of Electromagnetic induction
Factors which increased the induced current
Methods to produce induced emf
Important class 12th physics chapter 15 exercise for Intermediate part-II students.
What is Motional emf? Derive its Relation
State and explain Faraday Law of Electromagnetic induction
Reason of negative sign in Faraday law
Important 12th physics chapter 15 exercise for Intermediate part-II students.
State and explain Lenz's Law
Lenz’s law and law of conservation of energy
What is Mutual Induction and derive the relation for mutual inductance.
Important 12th physics chapter 15 notes for Intermediate part-II students.
Factors on which mutual inductance depend.
What is Self- Induction? Derive its Relation.
Calculate the Energy stored in an Inductor in terms of magnetic field.
Important 12th class physics chapter 15 short questions for Intermediate part-II students.
Energy in terms of magnetic field/Energy density
What is AC Generator? Describe its principle construction and working. Also derive equation of induced current and induced emf.
Working and Expression for induced emf and induced current of AC generator.
What is DC generator? Write its principle, construction and working.
Important 12th physics chapter 15 numericals for Intermediate part-II students.
Major parts of DC generator.
Fluctuations in output of DC can be reduced by
What is Difference b/w AC generator and DC generator?
What is Back motor effect in generator?
Important 12th class physics chapter 15 important questions for Intermediate part-II students.
Write a note on DC Motor.
What is difference between motor and generator?
Does the induced emf always act to decrease the magnetic flux through a circuit?
When the switch in the circuit is closed a current is established in the coil and the metal ring jumps upward why? Describe what would happen to the ring if the battery polarity were reversed?
Important 12th class physics chapter 15 exercise solutions for Intermediate part-II students.
The Fig shows a coil of wire in the xy plane with a magnetic field directed along the y-axis. Around which of the three coordinate axes the coil should be rotated in order to generate an emf and a current in the coil?
How would you position a flat loop of wire in a changing magnetic field so that there is no emf induced in the loop?
In a certain region the earth’s magnetic field point vertically down. When a plane flies due north, which wingtip is positively charged?
Important 12th Class physics chapter 15 objective for Intermediate part-II students.
When an electric motor, such as an electric drill, is being used, does it also act as a generator? If so what is the consequence of this?
Can a D.C motor be turned into a D.C generator? What changes are required to be done?
Is it possible to change both the area of the loop and the magnetic field passing through the loop and still not have an induced emf in the loop?
Important 12th class physics chapter 15 question answer for Intermediate part-II students.
Can an electric motor be used to drive an electric generator with the output from the generator being used to operate the motor?
A suspended magnet is oscillating freely in a horizontal plane. The oscillations are strongly damped when a metal plate is placed under the magnet. Explain why this occurs?
Four unmarked wires emerge from a transformer. What steps would you take to determine the turn’s ratio?
Can a step-up transformer increase the power level?
Transformer, there is no transfer of charge from the primary to the secondary. How is, then the power transferred?
When the primary of a transformer is connected to a.c mains the current in it. (a) Is very small if the secondary circuit is open, but (b) increases when the secondary circuit is closed. Explain these facts
An emf of 0.45V is induced between the ends of a metal bar moving through a magnetic field of 0.22T. What field strength would be needed to produce an emf of 1.5V between the ends of the bar, assuming that all other factors remain the same?
The flux density B in a region between the pole faces of a horseshoe magnet is 0.5 Wbm-2 directed vertically downward. Find the emf induced in a straight wire 5.0 cm long, perpendicular to B when it is moved in a direction at an angle of 60o with the horizontal with a speed of 100 cms-1.
A coil of wire has 10 loops. Each loop has an area of 1.5 x 10^-3 m^2 . A magnetic field is perpendicular to the surface of each loop at all times. If the magnetic field is changed from 0.05T to 0.06T in 0.1, find the average emf induced in the coil during this time.
A Circular coil has 15 turns of radius 2cm each. The plane of the coil lies at 40 to a uniform magnetic field of 0.2 T. If the field is increased by 0.5T in 0.2s, find the magnitude of the induced emf.
Two coils are placed side by side. An emf of 0.8 V is observed in one coil when the current is changing at the rate of 200 As^-1 in the other coil. What is the mutual inductance of the coils?
A pair of adjacent coils has a mutual inductance of 0.75 H. If the current in the primary changes from 0 to 10A in 0.025s, what is the average induced emf in the secondary? What is the change in flux in it if the secondary has 500 turns?
A solenoid has 250 turns and its self-inductance is 2.4 mH. What is the flux through each turn when the current is 2 A? What is the induced emf when the current changes at 20As^-1?

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