EASY
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The magnetic flux through each turn of a coil having turns is given as where is in second. The emf induced in the coil at is
(a)0.7 V
(b)1.2 V
(c)0.8 V
(d)0.9 V

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Important Questions on Electromagnetic Induction
MEDIUM
A planar loop of wire rotates in a uniform magnetic field. Initially, at , the plane of the loop is perpendicular to the magnetic field. If it rotates with a period of about an axis in its plane then the magnitude of induced emf will be maximum and minimum, respectively at:

MEDIUM
A very long solenoid of radius is carrying current as a function of time Counterclockwise current is taken to be positive. A circular conducting coil of radius is placed in the equitorial plane of the solenoid and concentric with the solenoid. The current induced in the outer coil is correctly depicted, as a function of time, by:

MEDIUM
At time magnetic field of is passing perpendicularly through the area defined by the closed loop shown in the figure. If the magnetic field reduces linearly to in the next then induced in the loop is:


EASY
The magnetic flux linked with a coil (in ) is given by the equation . The magnitude of induced emf in the coil at the fourth second will be:

MEDIUM
The figure shows a bar magnet and a metallic coil. Consider four situations. (I) Moving the magnet away from the coil. (II) Moving the coil towards the magnet. (III) Rotating the coil about the vertical diameter. (IV) Rotating the coil about its axis.

An emf in the coil will be generated for the following situations.

HARD
A light disc made of aluminium (a nonmagnetic material) is kept horizontally and is free to rotate about its axis as shown in the figure. A strong magnet is held vertically at a point above the disc away from its axis. On revolving the magnet about the axis of the disc, the disc will (figure is schematic and not drawn to scale)

HARD
A long solenoid of radius carries a time dependent current . A ring of radius is placed coaxially near its middle. During the time interval the induced current and the induced in the ring change as:

EASY
The magnetic flux through a circuit of resistance changes by an amount in time , Then the total quantity of electric charge . which is passing during this time through any point of the circuit is given by_____

EASY
A long solenoid of diameter has turns per meter. At the centre of the solenoid, a coil of turns and radius is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to from in . If the resistance of the coil is the total charge flowing through the coil during this time is

HARD
A conducting metal circular-wire-loop of radius is placed perpendicular to a magnetic field which varies with time as where are constants at time . If the resistance of the loop is , then the heat generated in the loop after a long time is

EASY
A conducting circular loop is placed in a uniform magnetic field, with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of . The induced emf when the radius is , is

MEDIUM
A uniform magnetic field is restricted within a region of radius, The magnetic field changes with time at a rate, . Loop one of radius encloses the region, and loop two of radius, is outside the region of magnetic field as shown in the figure below. Then the emf generated is


EASY
The magnetic flux through a coil varies with time as . The ratio of emf at to will be

EASY
A small bar magnet is moved through a coil at constant speed from one end to the other. Which of the following series of observations will be seen on the galvanometer attached across the coil?

HARD
A semicircular wire of radius rotates in uniform magnetic field about its diameter with angular velocity . If the total resistance of the circuit is , then the mean power generated per period of rotation is

EASY
Faraday's law among the following is ___.

EASY
The current in a coil of inductance changes from to in . The magnitude of the average induced emf in the coil is

MEDIUM
A turn coil of the effective area is kept perpendicular to the magnetic field When the plane of the coil is rotated by around any of its coplanar axis in the emf induced in the coil will be:

EASY
A coil of cross-sectional area having turns is placed in a uniform magnetic field . When it is rotated with an angular velocity the maximum e.m.f. induced in the coil will be:

HARD
A conducting square frame of side and a long straight wire carrying current are located in the same plane as shown in the figure. The frame moves to the right with a constant velocity . The e.m.f induced in the frame (when the centre of the frame is at a distance from the wire) will be proportional to :


