Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
electromagnetism
| Question | Answer |
|---|---|
| studies the force associated with e- in motion | electromagnetism |
| what are the ways we can induce current to flow within a conductor, as long as there is a potential difference | * moving conductor across a stationary magnetic field * cut a stationary conductor with magnetic lines of force * place a stationary conductor with a varying magnetic flux |
| what is Faraday's law | an electric current is induced to flow in a circuit if some part of the circuit is in a changing magnetic field |
| what factors control the amount of current generated within a conductor | * strength of magnet * speed or velocity of magnetic field past conductor * angle at which the magnetic field cuts the conductor * # of turns in conductor |
| when a conductor is perpendicular to the magnetic field, there is _______ current flow and when the conductor is parallel to the magnetic field there is _______ current flow | * no * maximum |
| what is Lenz's law | induced current flows in a direction that is opposite the action that induces it |
| what are the devices that work using electromagnetic induction | * helix * solenoid * elctromagnet |
| helix | coil of wire (ex. tube filament) |
| solenoid | coil of wire connected to source and carries current which sets up a magnetic field (ex. locks- bucky, detent, tube) |
| electromagnet | coil of wire carrying a current with an iron core (ex. remote control device, detent locks, fire doors |
| uses a single coil of wire with constant potential difference | elctromagnetic self induction |
| what is the purpose of the autotransformer | sits on the primary side of circuit/kVp selector/works off EM self induction |
| uses two coils of wire(primary and secondary)/step up or step down | electromagnetic mutual induction |
| *potential difference creates current flowing *sets up magnetic field that cuts through 2nd coil to induce opposing potential difference and induced current | primary coil |
| *carries induced current *induced current creates magnetic field around 2nd coil that cuts 1st coil to keep current flowing *no moving parts or contact | secondary coil |
| step up (high tension) transformer | works off EM mutual induction/ increases voltage to kVp/ decreases amperage to milliamps(to prevent blowing trasformer)/ more turns on secondary coil/ high tension transformer |
| step down (filament) transformer | works off EM mutual induction/ decreases kVp to voltage(6-10 volts)/ increases mA back to amperage(3-5 amps for overhead and .5-5 mA for fluoro/ more turns on primary coil/ used to produce filament current/attached to filament of tube on secondary side |
| converts mechanical to electrical energy | generator(dynamo) |
| converts electrical to mechanical energy *rotor | motor |
| what are the types of transformers, in order from weakest to strongest and what type of induction do they work off of | *air core *open core *closed core *shell type **all work of mutual induction |
| two coils of wire next to each other | air core transformer |
| two coils of wire, each with iron core inside coils | open core transformer |
| two coils of wire, each with its own iron core, the iron cores are connected @ bottom | closed core transformer |
| primary and secondary coil are wrapped around the same iron core | shell type transformer |
| what are the transformer law formulas | *Vs/Vp=Ns/Np *Is/Ip=Vp/Vs |
| what causes transformer inefficiency | *resistance *hysteresis *eddy current |
| loss of power due to heat | resistance |
| loss of power due to changing magnetic field | hysteresis |
| loss of power due to alternating current | eddy current |
| what is done to reduce transformer inefficiency | cut and laminate cores |
Created by:
bigad1982
Popular Radiology sets