RAD Physics - Chapter 10

transformer

The high voltage that is required by an x-ray machine is produced by the __________.

mutual induction

A transformer works on the principle of ___________.

input, output

The primary coil is the __________ side of the transformer and the secondary coil is the __________ side.

number of turns, number of turns

The transformer law states that the emf induced in the secondary coil is to the emf in the primary coil, as the __________ in the secondary coil is to the __________ in the primary coil.

step up, higher voltage

A __________ transformer has more turns in the secondary coil than in the primary coil and therefore __________ is created in the secondary coil than is supplied to the primary coil.

step down, less voltage

A __________ transformer has fewer turns in the secondary coil than in the primary coil and therefore __________ is created in the secondary coil than was supplied to the primary coil.

energy

According to the law of conservation of energy, there can be no more __________ coming out of the transformer than was put in.

voltage, amperage

A step up transformer increases __________ and decreases __________.

voltage, amperage

A step down transformer decreases __________ and increases __________.

high potential difference

In a diagnostic x-ray machine, the transformer provides the _________ necessary for the electrons to be driven towards the anode with enough speed to create an x-ray photon

kV, mA

The step up transformer of an x-ray machine changes voltage into __________ and amperage into __________,

flux leakage

The leakage of magnetic flux in the air at the ends of the cores of a transformer is known as __________.

efficiency

The ratio of power output to power input of a transformer is known as __________.

copper loss

The loss of electrical power due to the resistance of the coils of a transformer is known as __________.

thicker, thinner

In a step up transformer, the primary winding carries a larger current so the wire must be __________ as compared to the secondary coil which carries a smaller current and therefore the wire may be __________.

eddy current

The swirling current created in the core which is induced by the magnetic flux is called an __________ .

hysteresis loss

The power loss of a transformer due to the energy necessary to overcome the opposition to change, exhibited by ferromagnetic materials, every time the magnetic field produced by the primary winding changes polarity is known as ___________.

autotransformer

The _________ varies input voltage to the transformer in order to control output voltage and therefore functions as the kV selector of an x-ray machine.

AC source, primary

The autotransformer is connected between the __________ and the __________ side of the transformer.

self induction

The autotransformer operates on the principle of __________.

primary

The secondary voltage of the autotransformer is applied to the __________ side of the main step up transformer.

filament

The __________ circuit of the x-ray tube carries the current needed to heat the filament.

tube

The __________ circuit of the x-ray tube carries the current passing between the cathode and anode.

choke coil

A __________ is a coil with a core whose position is able to be adjusted, which operates on the principle of self induction and was once used to regulate filament current in the x-ray tube.

rheostat

A __________ is a variable resistor designed to regulate filament current.

air core transformer

two insulated coils of wire side by side

open core transformer

two insulated coils of wire with an iron core side by side

closed core transformer

two coils wound around a square iron core

shell type transformer

primary and secondary coils wound around the central section of a core consisting of sheets of silicon steel with two rectangular cutouts

autotransformer

a single winding that serves as both the primary and secondary coil, with an adjustable number of windings on the secondary side

open core and air core

Which type of transformers have most flux leakage?

closed core

Which type of transformer is most commonly used in x-ray equipment?

yes

Is a transformer considered to be efficient?

by using copper wire of adequate diameter

How can copper loss be reduced?

using laminated silicon steel plates

How can eddy currents be reduced?