PHYSICS - electromagnets Flashcards Preview

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Flashcards in PHYSICS - electromagnets Deck (14)
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1
Q

When an electric current flows what does it create ???

A

Magnetic Field

2
Q

How do you strengthen the magnetic field ???

A

1) By wrapping the coil around an iron core
2) Adding more turns to the coils
3) Increasing the current flowing through the coil

3
Q

how are electromagnets different to bar magnets?

A

electromagnets can get turned on and off using a switch however bar magnets are permanent

4
Q

what is a relay?

A

an electricity operated switch

5
Q

when is a voltage produced?

A

when a magnet moves into a coil of wire

6
Q

what is electromagnet induction?

A

a process where a conductor placed in a changing magnetic field causes the production of a voltage across the conductor

7
Q

name 3 things to increase induced voltage

A

1) move the magnet faster
2) add more turns to the coil
3) increase the strength of the magnet

8
Q

when is a magnetic field created?

A

when an electric current moves through a coil wire

9
Q

what can plotting compasses be used to show?

A

the shape and direction of the magnetic field created by a coil of wire

10
Q

what is a solenoid?

A

a long thin spiral of wire used to produce a magnetic field

11
Q

what is the motor effect?

A

a current carrying wire or coil exerting force on a permanent magnet

12
Q

how can an electric motor be built?

A

using a coil of wire that is free to rotate between two opposite magnetic poles

13
Q

what do speakers contain?

A

both an electromagnet and a permanent magnet

14
Q

what do speakers contain both of?

A

a permanent magnet and an electromagnet