The phenomenon of electromagnetic induction has been technologically important application in the generation of alternating currents." Name the device which can generate alternating currents. Draw a neat diagram of it. A rectangular coil having an area vector A ¯ and number of turns N is rotating in a magnetic field B ¯ with angular speed ω . If θ be the angle made by the area vector A ¯ with the field B ¯ at time t . Derive an expression for alternating emf ε starting directly from Faraday's law. Draw a graph to show the generated e.m.f at the time 0 , T 4 . T 2 , 3 T 4 and T .

The device which generates a.c current using the phenomenon of electromagnetic induction is called a. c generator.A diagram of the device is given below: Given the number of turns in the coil= N . The magnetic field= B ¯ , Area of coil= A , angular speed = ω , the angle between the coil and the field at time t = θ . According to Faraday's law, the emf developed in the rotating coil is ε = - dϕ dt = d dt - NBA cosωt = - ( - NBAωsinωt ) = NBAωsinωt ........(1) If sinωt = 1 then ε = NBAω = ε 0 ( maximum ) , hence we get, ε = ε 0 sinωt or ε = ε 0 sinθ . this is the required equation. The graphical representation of the emf generated:

What is motional emf, Deduce an expression for it from the following diagram. If R be the resistance of the loop PQRS at agiven instant, what will be induced current at that instant? A straight conductor of length 0 . 1 m moves with a speed of 10 ms - 1 perpendicular to the magnetic field of induction 1 web / m 2 . Calculate the induced e.m.f. State Len's law.

An emf induced by the motion of the conductor across the magnetic field is a motional electromotive force. The equation is given by E = - vLB For this expression, the velocity, field, and length are mutually perpendicular. The minus sign is associated with the Lenz's law. Consider a straight conductor PQ as shown in the figure, moving in the rectangular loop PQRS a uniform and time-independent magnetic field B perpendicular to the plane of the system. Let us suppose the motion of the rod to be uniform at a constant velocity of v on a to frictionless surface. Thus, the rectangle PQRS forms a closed circuit enclosing a varying area due to the motion of the rod PQ The magnetic flux ϕ B enclosed by the loop PQRS can be given as ϕ B = Blx . Where, RQ = x and RS = l Since the conductor is moving, x i s changing with time. Thus, the rate of change of flux ϕ B will induce an emf, which is given by: ε = - dϕ B dt = - d dt Blx = - Bl dx dt = - Blv ...............(A) Where the speed of the conductor PQ = v = dx dt . This is the expression of the motional emf due to the motion of a conductor in a magnetic field. The current in the conductor is given by I = E R = Blv R Given the length of the conductor i = 0 . 1 m . The speed of the conductor v = 10 ms - 1 The magnetic field B = 1 Web / m 2 , The motional emf is e = - Blv = - 1 × 0 . 1 × 10 = - 1 V .

What is motional emf, Deduce an expression for it from the following diagram. If R be the resistance of the loop PQRS at agiven instant, what will be induced current at that instant? A straight conductor of length 0 . 1 m moves with a speed of 10 ms - 1 perpendicular to the magnetic field of induction 1 web / m 2 . Calculate the induced e.m.f. State Len's law.

An emf induced by the motion of the conductor across the magnetic field is a motional electromotive force. The equation is given by E = - vLB For this expression, the velocity, field, and length are mutually perpendicular. The minus sign is associated with the Lenz's law. Consider a straight conductor PQ as shown in the figure, moving in the rectangular loop PQRS a uniform and time-independent magnetic field B perpendicular to the plane of the system. Let us suppose the motion of the rod to be uniform at a constant velocity of v on a to frictionless surface. Thus, the rectangle PQRS forms a closed circuit enclosing a varying area due to the motion of the rod PQ The magnetic flux ϕ B enclosed by the loop PQRS can be given as ϕ B = Blx . Where, RQ = x and RS = l Since the conductor is moving, x i s changing with time. Thus, the rate of change of flux ϕ B will induce an emf, which is given by: ε = - dϕ B dt = - d dt Blx = - Bl dx dt = - Blv ...............(A) Where the speed of the conductor PQ = v = dx dt . This is the expression of the motional emf due to the motion of a conductor in a magnetic field. The current in the conductor is given by I = E R = Blv R Given the length of the conductor i = 0 . 1 m . The speed of the conductor v = 10 ms - 1 The magnetic field B = 1 Web / m 2 , The motional emf is e = - Blv = - 1 × 0 . 1 × 10 = - 1 V .

The phenomenon of electromagnetic induction has been technologically important application in the generation of alternating currents." Name the device which can generate alternating currents. Draw a neat diagram of it. A rectangular coil having an area vector A ¯ and number of turns N is rotating in a magnetic field B ¯ with angular speed ω . If θ be the angle made by the area vector A ¯ with the field B ¯ at time t . Derive an expression for alternating emf ε starting directly from Faraday's law. Draw a graph to show the generated e.m.f at the time 0 , T 4 . T 2 , 3 T 4 and T .

The device which generates a.c current using the phenomenon of electromagnetic induction is called a. c generator.A diagram of the device is given below: Given the number of turns in the coil= N . The magnetic field= B ¯ , Area of coil= A , angular speed = ω , the angle between the coil and the field at time t = θ . According to Faraday's law, the emf developed in the rotating coil is ε = - dϕ dt = d dt - NBA cosωt = - ( - NBAωsinωt ) = NBAωsinωt ........(1) If sinωt = 1 then ε = NBAω = ε 0 ( maximum ) , hence we get, ε = ε 0 sinωt or ε = ε 0 sinθ . this is the required equation. The graphical representation of the emf generated:

Define coefficient of self induction and mutual induction and write their SI units

When the electric current in a coil changes, the magnetic flux linked with that coil also changes. Consequently, an emf is induced in the coil. This type of induction is called self-induction Induced emf e = L dI dt , Where L = coefficient of self-induction. We can define the coefficient of self-induction. as the ratio of the electromotive force produced in a circuit by self-induction to the rate of change of current producing, it expressed in henries. Unit of inductance= volt second ampere = Henri . Coefficient of mutual induction. A measure of the induction between two circuits; the ratio of the electromotive force in a circuit to the corresponding change of current in a neighbouring circuit; It is measured in henry. e = - M d I d t o r M = - - e d I d t

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Earn 100

Briefly explain working of a.c. generator.

Important Questions on Electromagnetic Induction

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EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 6 - Electromagnetic Induction>assam board-2019>Q 3

Define mutual induction of

1 Henry

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EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 6 - Electromagnetic Induction>assam board-2019>Q 4

Explain Lenz's law from the conservation of energy

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EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 6 - Electromagnetic Induction>assam board-2019>Q 5

The phenomenon of electromagnetic induction has been technologically important application in the generation of alternating currents." Name the device which can generate alternating currents. Draw a neat diagram of it.

A rectangular coil having an area vector $\bar{A}$ and number of turns $N$ is rotating in a magnetic field $\bar{B}$ with angular speed $ω$ . If $θ$ be the angle made by the area vector $\bar{A}$ with the field $\bar{B}$ at time $t$ . Derive an expression for alternating emf $ε$ starting directly from Faraday's law. Draw a graph to show the generated e.m.f at the time $0, \frac{T}{4} . \frac{T}{2}, \frac{3 T}{4} and T$ .

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EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 6 - Electromagnetic Induction>assam board-2020>Q 6

What is eddy current?

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EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 6 - Electromagnetic Induction>assam board-2020>Q 8

In a circuit current decrease from $5 A$ to $0 A$ is $0 \cdot 1 s$ . If the average induced e.m.f is $200 v$ , calculate the self inductance of the circuit and write is unit.

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EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 6 - Electromagnetic Induction>assam board-2020>Q 9

What do you mean by electromagnetic induction? Name the two great experimentalists who carried long series of experiments on electromagnetic induction. You are given two coils one galvanometer, one battery and some connecting wires. Describe a experiment that can show the production of electromagnetic induction.

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EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 6 - Electromagnetic Induction>assam board-2020>Q 10

What is motional emf, Deduce an expression for it from the following diagram. If $R$ be the resistance of the loop $PQRS$ at agiven instant, what will be induced current at that instant?

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A straight conductor of length $0.1 m$ moves with a speed of $10 {ms}^{- 1}$ perpendicular to the magnetic field of induction $1 web / m^{2}$ . Calculate the induced e.m.f. State Len's law.

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EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 6 - Electromagnetic Induction>assam board-2020>Q 11

Draw a labelled diagram of an AC generator. Show that it produces sinusoidal e,m,f, or current. What is the frequency of rotation in India,

Briefly explain working of a.c. generator.

Important Questions on Electromagnetic Induction

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