RAD-202 • Chapter 4 Quiz

The study of electric charges in motion is:

a. electromagnetism

b. electrodynamics

c. electronics

d. electrostatics

b. electrodynamics

As two charges get closer, the electrostatic force:

a. is directly proportional to the amount of distance between them

b. is inversely proportional to the amount of distance between them

c. is inversely proportional to the square of the distance between them

d. is directly proportional to the square of the distance between them

c. is inversely proportional to the square of the distance between them

Rubbing a rubber rod with fur is an example of electrification by:

a. contact

b. friction

c. induction

d. a. & c.

b. friction

The property of a circuit that impedes the flow of electrons is:

a. electric current

b. electric potential

c. resistance

d. electrostatics

c. resistance

The volt is the unit of measure for:

a. electric current

b. electric potential

c. resistance

d. electrostatics

b. electric potential

A material that allows electrons to move is a(n):

a. volt

b. insulator

c. conductor

d. inductor

c. conductor

Which of the following materials is a good conductor?

a. glass

b. copper

c. plastic

d. all of the above

b. copper

A battery produces:

a. alternating current

b. indirect current

c. direct current

d. current that changes direction

c. direct current

Ohm's Law can be written as:

a. amps = volts * ohms

b. volts = amps * ohms

c. ohms = volts * amps

d. none of the above

b. volts = amps * ohms

Ohm's Law can be written as:

a. I = V/R

b. I = R/V

c. R = I/V

d. R = IR

a. I = V/R

When a conductor has a smaller cross-sectional area:

a. resistance decreases

b. resistance increases

c. resistance remains the same

d. none of the above

b. resistance increases

When a conductor is more twisted:

a. resistance decreases

b. resistance increases

c. resistance remains the same

d. none of the above

c. resistance remains the same

Which of the following is not a good insulator?

a. glass

b. gold

c. wood

d. ceramic

b. gold

A material that will conduct electricity, but not as well as good conductors, but also will insulate, but not as well as good insulators, are called a(n):

a. excellent conductor

b. weak conductor

c. weak insulator

d. semiconductor

d. semiconductor

When a switch is turned on, the electric circuit:

a. is closed

b. does not allow electrons to flow

c. is opened

d. none of the above

a. is closed

An adjustable form of a resistor is the:

a. rheostat

b. capacitor

c. switch

d. diode

a. rheostat

Which of the following opens a circuit to keep the circuit & devices safe?

a. fuse

b. resistor

c. circuit breaker

d. a. & c.

d. a. & c.

Which of the following devices allow the electricity to flow in one direction only?

a. fuse

b. switch

c. transformer

d. diode

d. diode

The device that produces electrons through a chemical reaction is a:

a. transformer

b. fuse

c. resistor

d. battery

d. battery

The lines of force in space associated with a magnet are called:

a. lines of flux

b. dipoles

c. domains

d. lines of field

a. lines of flux

Like poles of a magnet __________ each other, & opposite poles __________ each other.

a. attract; attract

b. repel; repel

c. attract; repel

d. repel; attract

d. repel; attract

The force of magnetic attraction varies:

a. directly with the square of strength of the poles

b. inversely with the square of the strength of the poles

c. directly with the square of the distance between the poles

d. inversely with the square of the distance between the poles

d. inversely with the square of the distance between the poles

Magnetic field strength is measured in:

a. tesla (T)

b. ohms (Ω)

c. Newtons (N)

d. Joules (J)

a. tesla (T)

Wood & plastic are considered:

a. nonmagnetic

b. paramagnetic

c. ferromagnetic

d. diamagnetic

a. nonmagnetic

According to Faraday's Law of Electromagnetic Induction, if the strength of the magnetic field is increased, __________ is also increased.

a. current

b. resistance

c. voltage

d. all of the above

a. current

With self-induction, the secondary current:

a. is in a secondary coil

b. is in the original coil

c. opposes the original current

d. b. & c.

e. a. & c.

d. b. & c.

A transformer with 100 times more turns on the secondary side as compared with the primary:

a. is a step-up transformer

b. is a step-down transformer

c. is a transformer that works on self-induction

d. will have 100 times the current on the secondary side

a. is a step-up transformer

A transformer with 100 turns on the primary side & 50 turns on the secondary:

a. is a step-up transformer

b. is a step-down transformer

c. is a transformer that works on self-induction

d. will have 100 times the current on the secondary side

b. is a step-down transformer

The autotransformer:

a. uses self-induction

b. uses two coils of wire

c. does not use a magnetic core

d. is not typically found in an x-ray machine

a. uses self-induction

The autotransformer is found on the:

a. primary circuit

b. secondary circuit

c. filament circuit

d. none of the above

a. primary circuit

The line compensator is typically wired to the:

a. timer circuit

b. primary side of the high-voltage transformer

c. autotransformer

d. step-down transformer

c. autotransformer

The timer located on the secondary circuit is the:

a. synchronous timer

b. mAs timer

c. digital timer

d. none of the above

b. mAs timer

AEC stands for:

automatic exposure control

For AEC, the ionization chamber is placed between the __________ & __________.

a. tube; patient

b. patient; image receptor

c. grid; image receptor

d. image receptor; wall

b. patient; image receptor

The device that adjusts the incoming power supplied to the x-ray circuit to maintain 220 V is the:

a. circuit breaker

b. autotransformer

c. timer circuit

d. line compensator

d. line compensator

The solid-state rectifier has a(n) __________ crystal & a(n) __________ crystal.

a. a-type; b-type

b. x-type; z-type

c. a-type; c-type

d. p-type; n-type

d. p-type; n-type

Ripple refers to:

a. the fluctuation in amperage in the electricity

b. the fluctuation in voltage in the electricity

c. the fluctuation in resistance in the electricity

d. all of the above

b. the fluctuation in voltage in the electricity

Single-phase full-wave rectified current has:

a. 10% ripple

b. 25% ripple

c. 50% ripple

d. 100% ripple

d. 100% ripple

The purpose of the filament circuit is to:

a. produce high voltage

b. provide direct current to the x-ray tube

c. boil electrons off the filament

d. reduce the current reaching the filament

c. boil electrons off the filament

A general purpose radiographic tube typically has __________ filament(s).

a. 1

b. 2

c. 3

d. 4

b. 2

Electrostatics is the study of __________ electric charges, & electrodynamics is the study of electric charges in __________.

stationary; motion

The lines of flux travel from the __________ pole to the __________ pole inside the magnet & from the __________ pole to the __________ pole outside the magnet, creating elliptical loops.

south; north; north; south

When there is movement of some of the electrons of an uncharged metallic object as it is brought into the electric field of a charged object, this is electrification by:

a. contact

b. friction

c. induction

d. a. & b.

c. induction

The ampere is the unit of measure for:

a. electric current

b. electric potential

c. resistance

d. electrostatics

a. electric current

A volt is the ratio of work per unit of charge & is written:

a. Joules/Coulomb

b. Coulomb/Joules

c. Watt/Coulomb

d. Coulomb/Watt

a. Joules/Coulomb

Kilovoltage peak is abbreviated as:

kVp

A material that resists the movement of electrons is a(n):

a. ohm

b. insulator

c. conductor

d. inductor

b. insulator

Current that changes direction in the conductor is:

a. alternating current

b. indirect current

c. direct current

d. weak current

a. alternating current

The 60 Hz of electricity flowing into homes in the U.S. characterizes:

a. alternating current

b. indirect current

c. direct current

d. weak current

a. alternating current

A(n) __________ is the electrical resistance between two points along a conductor that, when 1 volt is applied, produces 1 ampere of current:

a. amp

b. volt

c. ohm

d. watt

c. ohm

When a metallic conductor is colder:

a. resistance decreases

b. resistance increases

c. resistance remains the same

d. none of the above

a. resistance decreases

Rubber is:

a. an excellent conductor

b. an excellent insulator

c. a weak conductor

d. a weak insulator

b. an excellent insulator

A device that temporarily stores charge is the:

a. rheostat

b. capacitor

c. transformer

d. fuse

b. capacitor

The ability of a material to attract iron, cobalt, or nickel is called:

a. electromagnetism

b. potential difference

c. magnetism

d. voltage

c. magnetism

Outside the magnet, the lines of flux travel from:

a. north pole to south pole

b. south pole to north pole

c. east pole to west pole

d. west pole to east pole

a. north pole to south pole

A material that is weakly repelled by a magnetic field is classified as:

a. nonmagnetic

b. paramagnetic

c. ferromagnetic

d. diamagnetic

d. diamagnetic

A material that is weakly attracted to a magnetic field is:

a. nonmagnetic

b. paramagnetic

c. ferromagnetic

d. diamagnetic

b. paramagnetic

Slowing down the speed at which the conductor passes through the magnetic field results in:

a. increased electromagnetic induction

b. reduced electromagnetic induction

c. no effect on electromagnetic induction

b. reduced electromagnetic induction

With mutual induction, to induce voltage in the secondary coil, there must be:

a. a physical connection between the two coils of wire

b. alternating current in the primary coil of wire

c. direct current in the primary coil of wire

d. a. & b.

e. a. & c.

b. alternating current in the primary coil of wire

Self-induction is based on the concepts introduced in:

a. Ohm's Law

b. Lenz's Law

c. Oersted's Law

d. Faraday's Law

b. Lenz's Law

A step-down transformer results in:

a. increased current

b. increased voltage

c. increased resistance

d. a. & b.

a. increased current

(decreased voltage)

A step-up transformer results in:

a. decreased current

b. decreased voltage

c. decreased resistance

d. a. & b.

a. decreased current

(increased voltage)

The x-ray tube (not filaments) is found on the:

a. primary circuit

b. secondary circuit

c. filament circuit

d. none of the above

b. secondary circuit

The filaments within the x-ray tube are found on the:

a. primary circuit

b. secondary circuit

c. filament circuit

d. none of the above

c. filament circuit

The only adjustable transformer in the x-ray circuit is the:

a. primary side of the high-voltage transformer

b. secondary side of the high-voltage transformer

c. autotransformer

d. step-down transformer

c. autotransformer

The timer that is based on a motor is the:

a. synchronous timer

b. mAs timer

c. digital timer

d. electronic timer

a. synchronous timer

The __________ converts volts to kilovolts.

a. step-up transformer

b. step-down transformer

c. autotransformer

d. none of the above

a. step-up transformer

When a negative charge is placed on the p-type crystal & a positive charge on the n-type crystal, the result is:

a. current flows through the diode

b. current does not flow through the diode

c. voltage decreases

d. voltage increases

b. current does not flow through the diode

Half-wave rectification:

a. suppresses half of the alternating current (AC) cycle

b. uses two rectifiers

c. is seldom used in modern x-ray equipment

d. all of the above

d. all of the above

Four rectifiers will produce:

a. alternating current

b. half-wave rectified current

c. full-wave rectified current

d. indirect current

c. full-wave rectified current

A pulsed direct current (DC) is produced by:

a. half-wave rectification

b. full-wave rectification

c. three-phase power

d. high-frequency generators

d. high-frequency generators

Adjusting the rheostat changes the __________ in the __________ circuit.

a. resistance; primary

b. voltage; primary

c. resistance; filament

d. voltage; filament

c. resistance; filament

mAs is:

a. another name for tube current

b. related to the amount of radiation exposing the patient

c. the product of mA & exposure time

d. b. & c.

d. b. & c.

The primary purpose of the step-down transformer is to:

a. decrease the voltage going to the filaments

b. decrease the amperage going to the filaments

c. increase the voltage going to the filaments

d. increase the amperage going to the filaments

d. increase the amperage going to the filaments

Determining which filament will be used during an exposure is done at the operating console by the selection of:

a. small or large focal spot

b. small or large filament

c. high or low exposure time

d. high or low kVp

a. small or large focal spot

Which of the following occurs first in the sequence of events leading to x-ray production?

a. voltage is stepped down & amperage increases

b. electron cloud is produced

c. current is adjusted by rheostat

d. electrons flow from cathode to anode

c. current is adjusted by rheostat

The selection of the large or small filament in the cathode depends on the choice of focal spot size at the operating console & the:

a. exposure time selected

b. kVp selected

c. mA station selected

d. all of the above

c. mA station selected

Electrification by induction requires that the two objects:

a. are in direct, constant contact with each other

b. are not at all in contact with each other

c. contact each other & then separate

d. are as far apart as possible from each other

b. are not at all in contact with each other

The flow of electrons along a conductor is:

a. electric current

b. electric potential

c. resistance

d. electrostatics

a. electric current

Glass is an example of a(n):

a. insulator

b. conductor

c. material that allows the flow of electrons

d. inductor

a. insulator

The device that regulates the amount of current flowing in the circuit is the:

a. battery

b. resistor

c. fuse

d. transformer

b. resistor

Increasing the strength of the magnetic field results in:

a. increased electromagnetic induction

b. reduced electromagnetic induction

c. no effect on electromagnetic induction

a. increased electromagnetic induction

The step-down transformer is found on the:

a. primary circuit

b. secondary circuit

c. filament circuit

d. none of the above

c. filament circuit