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Flashcards in Electromagnetism Deck (28)
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1

1. Who made the first battery?
2. What did he use?
3. How was it constructed?

1. Volta
2. Copper and zinc
3. Stacked like a Dagwood sandwich

2

__1__ passed current through a wire and put a __2__ near wire to demonstrate that a __3__ surrounds a wire carrying current.

1. Oersted
2. Compass
3. Magnetic Field

3

Left Hand Rule indicates direction of __1__that surround a current carrying wire. Thumb indicates __2__ of __3__ and fingers demonstrate __4__.

1. Flux lines
2. Direction
3. Current Flow
4. Direction of flux

4

_____=coil of wire

Helix

5

____=helix with a current

Solenoid

6

___=solenoid with ferromagnetic core

Electromagnet
EX: Transformer

7

Ways to induce a current in a wire:
A. Move a ___ over a wire
B. Move a wire through a ____
C. Allow wire to lie in __1__ varying __2__

A. Magnetic field
B. Magnetic field
C. 1. Magnetic field
2. Strength

8

Faraday's law says that current will be __1__ in a circuit in some part of it is in a __2__

1. Induced
2. Magnetic field

9

Magnitude of induced current in a wire depends on:
__1__ of magnetic field.
__2__ of wire as it moves in field.
__3__ of conductor.
__4__ of turns in conductor.

1. Strength
2. Velocity
3. Angle
4. Number

10

Transformer is used to vary __1__ & __2__

1. Current
2. Voltage

11

Rectifier converts __1__ to DC. Used in circuit because __2__ operates on DC but EVERYTHING else in circuit uses __3__.

1. AC
2. X-ray tube
3. AC

12

Generator and motor look identical=coil of wire (__1__) located within a magnetic field.

1. Armature

13

Generator=by rotating armature within the magnetic field, a __1__ is induced in __2__

1. Current
2. Armature

14

Motor=placing the charged armature in the __1__ will cause it to rotate due to a once or side __2__ on the wire.

1. Magnetic field
2. Thrust

15

AC Generators and Motors use __1__. DC generators and motors use a __2__.

1. Slip rings
2. Commutator ring

16

Induction motor spins __1__ in the X-ray tube. Stem is __2__ and parallel pairs of electromagnets surrounding rotor are __3__. Speed can be varied.

1. Anode
2. Rotor
3. Staters

17

These motors are used in clocks, ski lifts, ect. Spins at a constant speed.

Synchronous Motor

18

Step up transformer increases voltage and decreases __1__. Used to generate __2__ in a circuit. Less turns on __3__ (thicker) wire and more turns on the __4__ (thinner) wire. Works on AC, __5__ induction.

1. Amp
2. kV
3. Primary
4. Secondary
5. Mutual

19

Step down transformer decreases __1__ and increases __2__. Used to heat __3__ and generate __4__ n X-ray tube. More turns on the __5__ wire and less turns on the __6__. Works on AC, __7__ induction.

1. Voltage
2. Amp
3. Filament
4. MA
5. Primary
6. Secondary
7. Mutual

20

Transformer law

Vs/Vp=Ns/Np

21

Transformer Energy Lossess=Hysteresis, __1__ currents, and __2__ losses. __3__ of the core helps reduce loss.

1. Eddy
2. Copper
3. Lamination

22

Lamination is _____

Layering

23

Air core transformer=simplest type, most __1__, __2__ coils of wire __3__ (AC MUTAL)

1. Inefficient
2. Two
3. Side by side

24

Open core transformer=2 coils with ____ core

Iron

25

Closed core transformer=two coils wrapped around a round or square ____ core

Laminated

26

Shell type transformer=both could wrapped in __1__ of __2__ shaped block __3__ core. MOST __4__ and used __5__.

1. Center
2. Concrete
3. Laminated
4. Efficient
5. Most often

27

Autotransformer=AKA "__1__". Single wire wrapped around __2__ core. Tapped turns to __3__/__4__ voltage which is supplied to primary side of step up transformer. Works off of AC self induction.

1. KV Selector
2. Single
3. Increase
4. Decease

28

Right hand or __1__ Rule=thumb indicates __2__ of wire, Index indicates __3__ of magnetic field, middle indicates direction of __4__ flow.

1. Motor
2. Motion
3. Direction
4. Current