Midterm review Flashcards
What happens to current as you increase R
It decreases current
What happens when a ferromagnetic material is acted upon by an electromagnet?
All of the domains line up and the magnet is made into a permanent magnet
Can created permanent magnets be demagnetized/destroyed?
Yes
Do charges at rest create a magnetic field?
No
In order to induce a current in a circuit with a permanent magnet, what 2 things must happen?
The magnet must be moving w a DC current OR there must be an AC current supplied
How does electromagnetism work in a x ray motor?
- Current is run through stator, producing electromagnetism
- Creates a flow of current
- Creation of magnet in rotor
- Spinning occurs due to negative repelling rotor and stator
What is the number of e- emitted by the filament determined by?
The temperature of the filament, which is controlled by filament current
What does the AEC do?
A device that measures the quantity of radiation that reaches the IR and terminates the exposure when IR has received the required I
What changes during a step up transformer?
V increases
I decreases
What is half wave rectification?
When V is not allowed to swing negatively during negative half of its cycle (not what we use)
What are the cons of half wave and full wave rectification?
Require more or twice the exposure time, wastes half of the supply of power
What makes less anode heel affect?
Greater SID, shorter FOV
What does power rating usually describe?
HIgh V generators
Transformers
Describes power in KW
What is the hardest tube to position in a cross table lateral
floor mounted system
When you use rating charts, what do you use to find the HU?
kVp x mAs
