Unit 4 Review Flashcards
(31 cards)
Power Formula
P=IV
Power Loss
Ploss=(I^2) R
Ohms Law
V=IR
Example of a natural magnet
Earth
Ferromagnetic Define and Example
Highly permeable, strong attraction, easily magnetized
Ex: ordinary magnets
Paramagnetic
weak attraction to magnets
Ex: Aluminum
Diagmagnetic
Repelled by magnets
Ex: Lead, berillium, water
Non magnetic
no attraction to magnet/insulator
Ex: Plastic/rubber
3 Laws of Magnetisim
- all magnets have 2 poles, North and South
- like poles repel, unlike poles attract
- The forces of either attraction or repulsion are directly proportional to the strength of poles and inversely proportional to the distance between them
What happens if you break a magnet
The original north and south poles remain, new north and south poles opposite from the side of the break occur where the break happened
Once magnetized, do all elements remain permanently magnetized
no
What are the directions of the flux lines inside and outside magnets
Internal: South to North
External: North to South
Define EM induction
Generating eletrical current using a magnetic field
Define mutual induction
AC through primary coil creates a fluxuation magnetic field and that induces AC into 2ndary coil
What item in xray circuitry operates on mutual induction principle
Step up and step down transformers
Define Self Induction
Auto transformer-AC opposition of currents own flow because current reverses itself
Define permeability
Ease which a material is magnetized
Define retentivity
The ability of material to resist demagnetization
What kind of retentivity do we prefer for xray
low, we want the magnetism to decrease fast after exposure
Define magnetic dipoles/domains
Atoms with their magnetic field spinning the same direction
Helix
coil of wire
Solenoid
helix attatched to source of energy
Electromagnet
A solenoid with a ferromagnetic core
Where do we find solenoids and electromagnets used in an xray circuit
Transformers
Bucky lock
Tube detents
