Electromagnetic Induction - 1 - Free MCQ Practice Test with solutions,

electromagnetic induction i.e currents can be induced in coils (Select the best)

Predict the polarity of the capacitor in the situation described by fig.

A circular coil of radius 8.0 cm and 20 turns is rotated about its vertical diameter with an angular speed of 50 rad s^-1 in a uniform horizontal magnetic field of magnitude 3×10^-2 T. If the coil resistance is 10Ω, maximum emf induced in the coil,maximum value of current in the coil and average power loss due to Joule heating are

An ac generator consists of 8 turns of wire, each of area A=0.0900m² , and the total resistance of the wire is 12.0Ω. The loop rotates in a 0.500-T magnetic field at a constant frequency of 60.0 Hz. Maximum induced emf is

When a bar magnet is pushed towards the coil connected in series with a galvanometer, the pointer in the galvanometer G

There are two stationary coils near each other. If current in coil-1 is changing with time, relationship of current in coil-2 to it's emf is described by

A metallic rod of 1 m length is rotated with a frequency of 50 rev/s about an axis passing through the centre point O. Other end of the metallic rod slides on a Metallic ring . A constant and uniform magnetic field of 2 T parallel to the axis is present everywhere. What is the emf between the centre and the metallic ring?

Coils C₁ and C₂ are stationary. C₁ connected in series with a galvanometer while C₂ is connected to a battery through a tapping key. If the tapping key is pressed and released the galvaometer

Current in a circuit falls from 5.0 A to 0.0 A in 0.1 s. If an average emf of 200 V induced, estimate of the self-inductance of the circuit is

The magnetic field between the Horizontal poles of an electromagnet is uniform at any time, but its magnitude is increasing at the rate of 0.020T/s.The area of a horizontal conducting loop in the magnetic field is 120cm², and the total circuit resistance, including the meter, is 5Ω. Induced emf and the induced current in the circuit are

Kamla peddles a stationary bicycle the pedals of the bicycle are attached to a 100 turn coil of area 0.10m². The coil rotates at half a revolution per second and it is placed in a uniform magnetic field of 0.02 T perpendicular to the axis of rotation of the coil. What is the maximum voltage generated in the coil?

A pair of adjacent coils has a mutual inductance of 1.5 H. If the current in one coil changes from 0 to 20 A in 0.5 s, change of flux linkage with the other coil is

The magnetic field between the Horizontal poles of an electromagnet in is uniform at any time, but its magnitude is increasing at the rate of 0.020 T/s.The area of a loop made of perfect insulating material is 120cm².This loop is kept horizontally in the magnetic field. Induced emf and the induced current in the circuit are

If the polarity of induced emf is such that it tends to produce a current which aids the change in magnetic flux that produced it, which conservation law is violated?

A rectangular loop and a circular loop are moving out of a uniform magnetic field region to a field-free region with a constant velocity v as shown in fig. In which loop do you except  the induced EMF to be constant during the passage out of the field region if the field is normal to the loops.

A rectangular conductor PQRS in which the conductor PQ is free to move is kept in a magnetic field B ,which is perpendicular to the PQRS which lies in a single plane. If the conductor PQ has a length l,moves with a speed v, then induced emf is

A 500-loop circular wire coil with radius 4.00 cm is placed between the poles of a large electromagnet. The magnetic field is uniform and makes an angle of 60^∘ with the plane of the coil; it decreases at 0.200 T/s . Magnitude of induced emf is

Use Lenz’s law to determine the direction of induced current in the situations described by the Figure (a) A wire of irregular shape turning into a circular shape; (b) A circular loop being deformed into a narrow straight wire. The directions for (a) and (b) respectively are

An air-cored solenoid with length 30 cm, area of cross-section 25 cm² and number of turns 500, carries a current of 2.5 A. The current is suddenly switched off in a brief time of 10⁻³s. Average back emf induced across the ends of the open switch in the circuit is

If two coils of inductances L₁ and L₂ are linked such that their mutual inductance is M, then

Eddy Currents are

Polarity of the capacitor in the situation described by the adjacent figure is

A 1.0 m long metallic rod is rotated with an angular frequency of 400 rad s⁻¹ about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant and uniform magnetic field of 0.5 T parallel to the axis exists everywhere. Emf developed between the centre and the ring is

Two ends of a horizontal conducting rod of length l are joined to a voltmeter. The whole arrangement moves with a horizontal velocity v, the direction of motion being perpendicular to the rod. Vertical component of the earth's magnetic field is B. The voltmeter reads