Question

• Describe in your own words what induction means. Discuss how induction can be used to generate electricity.
• State Faraday's Law. Discuss a real-world application of Faraday's Law
• Explain the physical results of Lenz’s Law
• What are eddy currents? Discuss one application of eddy currents.
• A particle accelerator sends high-velocity charged particles down an evacuated pipe. Explain how a coil of wire wrapped around the pipe could detect the passage of individual particles.

Answer 1

(1)

Electromagnetic induction is the process of generating electric current with a magnetic field. Electromagnetic induction occurs when a circuit with an alternating current flowing through it generates current in another circuit simply by being placed nearby. An alternating current is the kind of electricity flowing through power lines and home wiring, as opposed to a direct current, which we get from batteries.

(2)

Faraday’s law states that a current will be induced in a conductor which is exposed to a changing magnetic field. Lenz’s law of electromagnetic induction states that the direction of this induced current will be such that the magnetic field created by the induced current opposes the initial changing magnetic field which produced it.

The most common applications of Faraday's Law of Induction are in Generator and in transformers, electrical bells.

(3)

Lenz's law states that the direction of an induced e.m.f. will be such that if it were to cause a current to flow in a conductor in an external circuit, then that current would generate a field that would oppose the change that created it.
(4)

Eddy currents are currents which circulate in conductors like swirling eddies in a stream. They are induced by changing magnetic fields and flow in closed loops, perpendicular to the plane of the magnetic field.

Application of eddy current:

Magnetic Levitation: It is a repulsive type of levitation finds application in modern high speed Maglev trains to provide frictionless transportation. Changing magnetic flux produced by a superconducting magnet placed on the moving train produces eddy currents on the stationary conducting sheet over which train levitates. The eddy currents interact with the magnetic field to produces forces of levitation.

(5)

when an individual particle or charge is passed through the coil an EMF is induced in it and the magnetic strength increases. This induced EMF will produce current in the coil. This current creates another field in opposite direction to resist the increase in magnetic strength.