Electromagnetic Induction Flashcards

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1
Q

Explain electromagnetic induction

A

The electrons of a conductor in a mag field experience a force causing them to accumulate at one end.
This induces an emf which induces a current

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2
Q

How is an emf induced in a magnetic field?

A

When there are changes in mag flux

lines of flux are cut

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3
Q

What does flux cutting result in?

A

Always induces emf

Induces current if complete circuit

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4
Q

What is flux linkage?

A

flux times no of turns in coil

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5
Q

What is faradays law

A

Induced emf is directly proportional to the rate of change of flux linkage

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6
Q

What is lenz’s law

A

Induced emf is always in a direction to oppose the change that caused

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7
Q

Why does induced emf oppose the change?

A

To conserve energy

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8
Q

How to investigate induced emf?

A

Dropping a magnet through a coil

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9
Q

What is NxFi and units?

A

Flux linkage , Wb

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10
Q

What is d(NxFi)/dt

A

=emf induced

Rate of change of flux linkage

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11
Q

An emf is only induced in a conductor when?

A

The magnetic flux linked with the coil changes

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12
Q

state lenzs law in terms of flix

A

Induced current flows to produce its own magnetic field and flux which acts im a direction to opposethe change in mag flux that occured to restore it to its original value

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13
Q

State lenzs law in terms of forces

A

Induced current flow to produce its own mag field, this interacts with external mag field to produce a force that opposes the original motion that induced the current

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