# Physics Unit 5 and 6 Review Flashcards Preview

## Physics > Physics Unit 5 and 6 Review > Flashcards

Flashcards in Physics Unit 5 and 6 Review Deck (35)
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1
Q

Motor

A

Turns electrical energy into mechanical

2
Q

Generator

A

Turns mechanical energy into electrical

3
Q

Step up Transformer

A

Increases voltage, decreases current

4
Q

Step down transformer

A

Decreases voltage, increases current

5
Q

Purpose of transformer

A

select applied KV

6
Q

Four types of transformers and define

A

Open core-iron cores inserted in coils
Air core-2 coils side by side
Shell-Cinderblock looking iron core and prism/second wrapped around center post of coil
Closed- one continuous loop of core with windings wrapped

7
Q

What transformer is least efficient

A

Air

8
Q

What transformer is most efficient

A

Shell

9
Q

Difference between air core and open core

A

Air core has no core and open core has ferromagnetic core

10
Q

What are transformers wrapped with to help improve efficiency

A

laminated silicon steel to hold in power

11
Q

3 ways to lose power in transformers

A

Copper-resistance in conductor itself because of diameter and length
Hysteresis: AC fluctuations and realignment of magnetic domain
Eddy: current swirling in the core

12
Q

Transformers work on what principle

A

Mutual induction

13
Q

What current works best with transformers

A

AC

14
Q

Transfomer Law

A

Vp/Vs=Np/Ns

15
Q

Purpose of Autotransfomers

A

select the KV

16
Q

Autotransfomers work on the principle of

A

Self induction

17
Q

How do you determine the amount of voltage per tapped turn

A

dividing total amount of voltage going into by the total turns

18
Q

auto transformers are also called

A

Variable ratio transformers

19
Q

3 phase 6 pulse formula

A

MAsxKVx1.35

20
Q

3 phase 12 pulse formula

A

MAsxKVx1.41

21
Q

What turns the rotor in an induction motor

A

rotating magnetic field

22
Q

Where do you find an induction motor in Xray equipment

A

target/xray tube

23
Q

What types of devices are syncronous motors found in

A

Clocks and timers

24
Q

What accelerates the electrons from the cathode to the anode

A

KVP or applied voltage

25
Q

The focusing cup can be made of what 2 metals

A

nickel

molybdenum

26
Q

Regular speed motor vs high speed

A

3600 to 10000-12000 RPMS

27
Q

Why are tungsten and thorium used as filament materials

A

high heat capacity, high atomic number, for longer ife

28
Q

What temp does thermoinic emission occur

A

2200°c

29
Q

Anode Heel Effect

A

absorbs reduction on intensity because the anode absorbs some of the beam

30
Q

Dual focus tubes

A

SFS/LFS detail

2 focal spot sizes in a tube

31
Q

Line focus principle

A

as long as the target angle is less than 45° the effective focal spot it was always be smaller than AFS

32
Q

What eventually causes the demise of xtray tubes

A

Fillament breaking-heat in general

33
Q

What are rotor bearings made out of that keeps them spinning smoothly

A

Metallic barium or silver

34
Q

Why is the tube immersed in oil

A

prevents shock and electrical insulation

35
Q

3 transformer types

A

auto
high tension
fillament