Electromagnetic Induction

Electromagnetic induction is change in ___________________. 

• surface area
• magnetic poles
• magnetic flux

What would happen if I move a bar magnet in and out of a coil of copper wire?

• Electric current would disappear 
• The magnet would explode 
• Electric current will flow through the wire
• It would produce a gravitational field

Which action will increase the deflection of the galvanometer pointer?

• The magnetic pole is reversed

• The number of turns of coils is increased

• The coil is made from insulated wire

• The magnet is slowly pushed into the coil

Which is the best method to determine the direction of the induced current?

• Fleming’s right-hand rule

• Fleming’s left-hand rule

Why there is no induced e.m.f or induced current if the straight wire moved parallel to the magnetic field?

• fields not touch the wire

• fields are stationary

• fields are not cut by the wire

• weaker fields

Below are the factors affecting the magnitude of induced e.m.f except...

• increases the speed of relative motion

• increases the number of turns of the solenoid

• decreases the strength of magnetic field

How to determine the polarity of the ends of the solenoid?

• 
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• 
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Faraday’s Law states that

• the magnitude of induced e.m.f is inversely proportional to the the rate of cutting of the magnetic field

• the magnitude of induced e.m.f is directly proportional to the the rate of cutting of the magnetic field

• the direction of induced e.m.f is inversely proportional to the the rate of cutting of the magnetic field

• the direction of induced e.m.f is directly proportional to the the rate of cutting of the magnetic field

Lenz’s Law states that the induced current always flows in a direction that oppose the change of magnetic flux that causes it.

• True

• False

• Not sure

Lenz's law obey...

• second's newton law of motion

• principle of conservation of energy

• total conservation of momentum