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Flashcards in Electromagnetism Deck (28)
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1
Q
  1. Who made the first battery?
  2. What did he use?
  3. How was it constructed?
A
  1. Volta
  2. Copper and zinc
  3. Stacked like a Dagwood sandwich
2
Q

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

A
  1. Oersted
  2. Compass
  3. Magnetic Field
3
Q

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

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

_____=coil of wire

A

Helix

5
Q

____=helix with a current

A

Solenoid

6
Q

___=solenoid with ferromagnetic core

A

Electromagnet

EX: Transformer

7
Q

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

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

8
Q

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

A
  1. Induced

2. Magnetic field

9
Q
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.
A
  1. Strength
  2. Velocity
  3. Angle
  4. Number
10
Q

Transformer is used to vary __1__ & __2__

A
  1. Current

2. Voltage

11
Q

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

A
  1. AC
  2. X-ray tube
  3. AC
12
Q

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

A
  1. Armature
13
Q

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

A
  1. Current

2. Armature

14
Q

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

A
  1. Magnetic field

2. Thrust

15
Q

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

A
  1. Slip rings

2. Commutator ring

16
Q

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.

A
  1. Anode
  2. Rotor
  3. Staters
17
Q

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

A

Synchronous Motor

18
Q

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.

A
  1. Amp
  2. kV
  3. Primary
  4. Secondary
  5. Mutual
19
Q

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.

A
  1. Voltage
  2. Amp
  3. Filament
  4. MA
  5. Primary
  6. Secondary
  7. Mutual
20
Q

Transformer law

A

Vs/Vp=Ns/Np

21
Q

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

A
  1. Eddy
  2. Copper
  3. Lamination
22
Q

Lamination is _____

A

Layering

23
Q

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

A
  1. Inefficient
  2. Two
  3. Side by side
24
Q

Open core transformer=2 coils with ____ core

A

Iron

25
Q

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

A

Laminated

26
Q

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

A
  1. Center
  2. Concrete
  3. Laminated
  4. Efficient
  5. Most often
27
Q

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.

A
  1. KV Selector
  2. Single
  3. Increase
  4. Decease
28
Q

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

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