List of top Physics Questions on Electromagnetic induction

Two conducting circular loops A and B are placed in the same plane with their centres coinciding as shown in figure. The mutual inductance between them is:

A small square loop of wire of side \( \ell \) is placed inside a large square loop of wire of side \( L \) ( \( L = \ell^2 \) ). The loops are coplanar and their centers coincide.The value of the mutual inductance of the system is \( \sqrt{x} \times 10^{-7} \, \text{H} \), where \( x = \) _____.

A coil is placed perpendicular to a magnetic field of 5000 T. When the field is changed to 3000 T in 2s, an induced emf of 22 V is produced in the coil. If the diameter of the coil is 0.02 m, then the number of turns in the coil is :

A power transmission line feeds input power at 2.3 kV to a step down transformer with its primary winding having 3000 turns. The output power is delivered at 230 V by the transformer. The current in the primary of the transformer is 5A and its efficiency is 90%. The winding of transformer is made of copper. The output current of transformer is_____A.

Primary side of a transformer is connected to 230 V, 50 Hz supply. Turns ratio of primary to secondary winding is 10 : 1. Load resistance connected to secondary side is 46 \(\Omega \). The power consumed in it is :

If the total energy transferred to a surface in time \( t \) is \( 6.48 \times 10^5 \, \text{J} \), then the magnitude of the total momentum delivered to this surface for complete absorption will be :

A rectangular loop of sides 12 cm and 5 cm, with its sides parallel to the x-axis and y-axis respectively, moves with a velocity of 5 cm/s in the positive x-axis direction, in a space containing a variable magnetic field in the positive z direction.
The field has a gradient of \(10^{-3}\) T/cm along the negative x direction, and it is decreasing with time at the rate of \(10^{-3}\) T/s. If the resistance of the loop is 6 mΩ, the power dissipated by the loop as heat is \(\_\_\_\_\_\_ \times 10^{-9}\) W.

Two coils have mutual inductance 0.002 H. The current changes in the first coil according to the relation \( i = i_0 \sin \omega t \), where \( i_0 = 5 \, \text{A} \) and \( \omega = 50\pi \, \text{rad/s} \). The maximum value of emf in the second coil is \( \frac{\pi}{\alpha} \). The value of \( \alpha \) is ______.

A rectangular loop of length 2.5 m and width 2 m is placed at 60° to a magnetic field of 4 T. The loop is removed from the field in 10 sec. The average emf induced in the loop during this time is:

A ceiling fan having 3 blades of length 80 cm each is rotating with an angular velocity of 1200 rpm. The magnetic field of earth in that region is 0.5 G and the angle of dip is \( 30^\circ \). The emf induced across the blades is \( N \pi \times 10^{-5} \, \text{V} \). The value of \( N \) is \( \_\_\_\_\_ \).

A square loop of side \( 10 \, \text{cm} \) and resistance \( 0.7 \, \Omega \) is placed vertically in the east-west plane. A uniform magnetic field of \( 0.20 \, \text{T} \) is set up across the plane in the northeast direction. The magnetic field is decreased to zero in \( 1 \, \text{s} \) at a steady rate. Then, the magnitude of the induced emf is \( \sqrt{x} \times 10^{-3} \, \text{V} \). The value of \( x \) is _____.

A horizontal straight wire 5 m long, extending from east to west, is falling freely at a right angle to the horizontal component of Earth's magnetic field \( 0.60 \times 10^{-4} \, \text{Wb/m}^2 \). The instantaneous value of emf induced in the wire when its velocity is \( 10 \, \text{m/s} \) is _______ \( \times 10^{-3} \, \text{V} \).

A long solenoid of diameter 0.1 m has 2 × 10⁴ turns per meter. A coil of 100 turns and radius 0.01 m is placed with its axis coinciding with the solenoid axis.The current in the solenoid reduces at a constant rate to 0 A from 4 A in 0.05s .If the resistance of the coil is 10π²Ω, then the total charge flowing through the coil during this time is ______.
Fill in the blank with the correct answer from the options given below.

A 50 Hz AC current of crest value 1 A flows through the primary of a transformer. If the mutual inductance between the primary and secondary is 0.5 H, the crest voltage induced in the secondary is______.
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A conducting ring of radius r is placed in a varying magnetic field perpendicular to the plane of the ring. If the rate at which the magnetic field varies is x, the electric field intensity at any point of the ring is________.
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A wire of irregular shape in figure (a) and a circular loop of wire in figure (b) are placed in different uniform magnetic fields as shown in the figures below. In figure (a), the magnetic field is perpendicular into the plane. In figure (b), the magnetic field is perpendicular out of the plane.

The wire in figure (a) is turning into a circular loop and that in figure (b) into a narrow straight wire. The direction of induced current will be _____.
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In a pair of adjacent coils, for a change of current in one of the coils from 0 A to 10 A in 0.25 s, the magnetic flux in the adjacent coil changes by 15 Wb. The mutual inductance of the coils is ________.
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In an AC circuit, the current leads the voltage by \(\frac{\pi}{2}\) The circuit is _______.
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Match List-I has four graphs showing variation of opposition to flow of ac versus frequency with circuit characteristic in List-II.

The phenomenon of electromagnetic induction involves the process of

A wire of length $1 m$ moving with velocity $8 m / s$ at right angles to a magnetic field of $2 T$ The magnitude of induced emf, between the ends of wire will be ______

A small square loop of wire of side $l$ is placed inside a large square loop of wire $L ( L >>l)$ Both loops are coplanar and their centers coincide at point $O$ as shown in figure The mutual inductance of the system is :

A conducting circular loop of radius $\frac{10}{\sqrt{\pi}} cm$ is placed perpendicular to a uniform magnetic field of $0.5 T$ The magnetic field is decreased to zero in $0.5 s$ at a steady rate The induced emf in the circular loop at $0.25 s$ is:

A metallic rod of length ' $L$ ' is rotated with an angular speed of ' $\omega$ ' normal to a uniform magnetic field ' $B$ ' about an axis passing through one end of rod as shown in figure The induced emf will be :