Induced Electric Field

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Induced Electric Field: Overview

This topic covers concepts, such as Properties of Induced Electric Field, Induced Electric Field Due to Time Variable Magnetic Field in Cylindrical Region, and Induced Electric Field.

Important Questions on Induced Electric Field

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A conducting ring of radius a is kept in x-y plane with its centre at origin. A time varying magnetic field given by B=B0t-k^ is applied in this region. An ideal voltmeter is connected between two points of the ring in two different cases as shown.

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If πB0a2=8 V and voltmeter reading in case I and case II is VI and Vll respectively, then

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As shown, a uniform magnetic field B pointing out of paper plane is confined in the cylindrical region of cross-section radius r. At a distance R from the center of shaded area there is point particle of mass m and carrying charge q. The magnetic field is then quickly changed to zero. The speed of particle just after magnetic field reduces to zero is?

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Take: Initial magnetic field B = 6T
Charge q = 80 mC
Radius r = 5cm, R = 10cm
Mass of particle = 2 gram.

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The figure shows the cross section of a cylindrical region of radius R in which the magnetic field points into the page. The magnitude of the field is 1 T at time t=0 and it decreases to zero in 20 seconds.

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The induced electric field at a distance r from the centre O inside the cylindrical region is given by

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A thin non-conducting ring of mass m and radius a currying a charge q can rotate freely about its own axis which is vertical. At the initial moment the ring was at rest in horizontal position and no magnetic field was present. At instant t=0, a uniform magnetic field is switched on which is vertically downward and increases with time according to the law B=B0t. Neglecting magnetism induced due to rotational motion of ring.

Angular acceleration of the ring is:

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The circular wire in figure below encircles solenoid in which the magnetic flux is increasing at a constant rate out of the plane of the page.

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The clockwise emf around the circular loop is ε0. By definition a voltammeter measures the voltage difference between the two points given
by Vb-Va=-abE·ds. We assume that a and bare infinitesimally close to each other. The values of Vb-Va along the path 1 and Va-Vb along the path 2, respectively are

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A uniform but time-varying magnetic field B(t) Exists in a circular region of radius 'a' And is directed into the plane of the paper, as shown. The magnitude of the induced electric field at point P At a distance r From the centre of the circular region

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Figure shows a uniform magnetic field B confined to a cylindrical volume and increasing at a constant rate. The instantaneous acceleration experienced by an electron placed at P is-

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A solenoid of radius R and length L has a current I=I0 cos ωt. The value of induced electric field at a distance of r outside the solenoid, is:

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A uniform but time varying magnetic field B=2t3+24t is represent in a cylindrical region of radius R=2.5 cm as shown in fig.

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The force on an electron at P at t=2sec. is

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Figure shows an irregular shapped wire AB moving with velocity v. Find the emf induced in the wire :-

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As shown in the above figure, there is a uniform magnetic induction B parallel to the axis of a cylindrical space of radius R. Plot the graph between the induced electric field and distance r from the axis of the cylinder, if it is known that the rate of change of magnetic induction is constant.

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As shown in the above figure, consider a closed-loop held in a magnetic field. The change in the magnetic flux linked with the loop induces a voltage V in the loop. Now, find the work done in taking a charge Q over a complete loop:

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Consider a cylindrical region of radius R, where a uniform magnetic field of induction B is confined. At point P, a negative charge of magnitude e is placed. Find the acceleration of the charge, if dBdt=C, where C is a constant.

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As shown in the above figure, a loop surrounds three regions of the magnetic field where the magnitude of the magnetic field is decreasing at a constant rate α. Take the area of each region as A. Now find the E.dl along the given loop, where E is the induced electric field.

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Consider the uniform magnetic field of magnitude 0.01 T directed perpendicularly to the plane of a conducting ring of the radius 1 m. If the ring is oscillating with a frequency of 0.1 kHz, then find the induced electric field.

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Consider a q charged ring of radius b and mass m in x-y plane with its centre at the origin. There is a magnetic field B which is confined to a region ra and points out of the paper. Here, r=0 is origin and a<b. If this magnetic field is brought to zero in time Δt, then find the angular velocity of the ring after the field vanishes,

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A thin non-conducting ring of mass m and radius a carrying a charge q can rotate freely about its own axis which is vertical. At the initial moment the ring was at rest in horizontal position and no magnetic field was present. At instant t=0, a uniform magnetic field is switched on which is vertically downward and increases with time according to the law B=B0t. Neglecting magnetism induced due to rotational motion of ring.

Angular acceleration of the ring is:

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A parabola y=kx2 shaped wire is placed in aperpendicular uniform magnetic field of induction B. At t = 0, wire starts moving from the vertex O with a constant acceleration linearly as shown in figure.Then emf induced in the loop will be-

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A uniform disc of radius r and mass m is charged uniformly with the charge q. This disc is placed flat on a rough horizontal surface having coefficient of friction μ. Find the time in second after which the disc begins to rotate when a uniform magnetic field is present in a circular region of radius a (>r) but varying as kt3 as shown in figure. (Given r=1 m, m=18 kg, μ=0.1, k=4, g=10 m s-2). 

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There is a non conducting ring of radius R and mass m having charge q uniformly distributed over its circumference. It is placed on a rough horizontal surface. A vertical time varying uniform magnetic field B=4t2 is switched on at time t=0. The coefficient of friction between the ring and the table, if the ring starts rotating at t=1sec, is