Quiz 4

Question 0

Permeability

Answer 0

• susceptibility to magnetization

* how easy a substance becomes magnetized

Question 1

Magnetism

Answer 1

•the ability to attract iron, cobalt, nickel

Question 2

Retentivity

Answer 2

•how well it retains the magnetism

Question 3

Ferromagnetic

Answer 3

• magnetic material (iron, cobalt, nickel) high permeability
• can become permanent magnets
• alnico is a type of this
• highly magnetized

Question 4

Paramagnetic

Answer 4

• feebly attracted by magnet
• low permeability
• platinum

Question 5

Diamagnetic

Answer 5

• feebly repelled by magnet

* beryllium & bismuth

Question 6

Non magnetic (diamagnetic)

Answer 6

• no magnetic attraction

* wood, plastic, glass

Question 7

Electromagnetic induction

Answer 7

•moving magnetic fields can produce electric current

Question 8

Magnetism poles

Answer 8

•every magnet has 2 poles north seeking & south seeking

Question 9

Magnetism (attraction)

Answer 9

•unlike poles

Question 10

Electromagnetic induction (produced)

Answer 10

• when a conductor is cut by moving lines of flux
• conductor moves across stationary lines of flux
• produced only when magnetic field or conductor move

Question 11

Generator

Answer 11

•a device that converts mechanical energy to electrical energy

Question 12

Magnetism (repulsion)

Answer 12

•like poles

Question 13

Magnitude depends on..

Answer 13

• Speed-# of lines cut per sec. The more lines the higher emf
• Strength-# of lines per cm(square)
• Angle-the angle between conductor & direction of magnetic field, the closer to 90* the stronger emf
• Turns(coils)-# of turns in conductor EMF directly proportional to # of turns

Question 14

If u have a coil of wire and u place an iron bar/ iron core in it, apply current you get?

Answer 14

•electromagnet

Question 15

AC motors

Answer 15

• synchronous-steady speed good for clocks but not very powerful
• induction(squirrel cage)-stator/rotor

Question 16

Transformer works off of what kind of induction

Answer 16

• mutual induction

* a current flowing through one will induce a current in the other

Question 17

• increases voltage

* decreases amperage

Answer 17

•Step up

Question 18

Generator (features)

Answer 18

• Magnetic field-permanent or electromagnet
• Armature-a coil of wire, around a core, rotated mechanically through magnetic fields
• Commutator (brushes)-slip rings
• Kinesis-mechanical energy to turn armature “crank,motor,windmill”

Question 19

Most/least efficient transformer?

Answer 19

• shell core- 2 rectangular openings with coil in center submerged in oil
• air core-coil side by side

Question 20

Transformer powerloss due to?

Answer 20

• diameter of wire
• length of conductor
• # of windings
• p=i(square)R

Question 21

Lines of force (Flux)

Answer 21

• line of magnetic force surrounding magnet

* the more lines the stronger the magnet

Question 22

Magnetic classification

Answer 22

• ferromagnetic
• paramagnetic
• diamagnetic

Question 23

• Decreases voltage

* increases amperage

Answer 23

•step down

Question 24

Magnetic induction

Answer 24

•Magnetic material brought near a magnet becomes temporary magnetized through induction

Question 25

AC current flowing in a conductor induces a current in a adjacent conductor, not electrically connected.

Answer 25

•mutual induction

Question 26

Commutator brushes

Answer 26

• slip rings
• usually carbon
• connected at the ends of coil
• rectifies AC to DC

Question 27

Transformer input primary (coil supplied by

Answer 27

•AC

Question 28

Dielectric constant

Answer 28

•A true

Question 29

Useful wavelength for xray

Answer 29

.1-.5 Å

Question 30

Does distance have anything to do with quality of xray

Answer 30

•no distance does no effect X-ray quality

Question 31

Split rings are used by AC or DC generators?

Answer 31

•DC generators