Looks like no one added any tags here yet for you.
who invented the battery
volta
who discovered that an electric current produces a magnetic field
oersted
who discovered that current is induced by a moving magnetic field
faraday
what is the law that states the induced current flows in the opposite direction of the applied current
lenz law
what is the right thumb rule
direction of the thumb=direction of current; direction of fingers=direction of magnetic field
what is a solenoid
helix with a current
what is a helix
coil of water
what is an electromagnet
solenoid with an iron core
what is self induction
the induction of an opposing EMF in a single coil by its own changing magnetic field
what is mutual induction
magnetic field induces a current in a nearby helix
what are the forms of power loss
copper, hysteresis, eddy current
how is hysteresis a power loss
rearranges magnetic domains
what is an eddy current
swirling currents in the core, minimized by lamination of plates
what is the result of no motion of a magnet or wire when trying to induce a current?
no current
what converts mechanical energy to electrical energy
a generator
how does an autotransformer accomplish voltage regulation
submerged in oil to reduce shockw
what happens to a generator if the magnetic field is increased? decreased?
When the magnetic field is increased, the induced EMF and current output increase. if the magnetic field is decreased, the induced EMF and current output decrease.
what transformer is used in modern x-ray equipment
step up and step down transformer
what is a step up & step down transformer
used to change the magnitude of current and voltage; mutual induction
how does a step up transformer operate
found in tube circuit; primary power→ secondary power, less coils→ more coils, power increase
how does a step down transformer operate
found in filament circuit; primary power → secondary power, more coils→ less coils, power decrease
what is the relationship between the number of loops in a generator and current
a higher number of loops directly correlates to a higher induced current; directly proportional
what magnetic field angle will give the most intensity (current)
90º
what is an air core transformer
not very efficient, only two coils
what is an open core transformer
addition of an iron core increases the strength of the magnetic field
what is a closed core transformer
closed iron core
what is a shell type transformer
most efficient; 95% efficient
what converts electrical energy to mechanical energy
a motor
what type of motor does the rotating anode use
induction motor; stator and rotor
what are the two motor types
synchronous and induction
what is a synchronous motor
coil rotates at same frequency as current; used in timing circuits in older x-ray machines
what is a induction motor
stator and rotor; uses electromagnets to create magnetic field to interact with current’s magnetic field
what is potential difference
electromotive force (voltage), force that causes charges to move; electrical push or pull
what is the transformer law: voltage formula
Vp/Vs=Np/Ns
what is the transformer law: amperage formula
Is/Ip=Np/Ns
how does an alternating current generator operate with 60 Hz and 120 alternations (impulses)
a frequency has 60 Hz therefore 60 cycles/second, each cycle has 2 alternations therefore 60Hz has 120 alternations