Electricity

Question 1

The type of current in which electrons alternate direction of flow as the electric potential switches back and forth

Answer 1

Alternating current

Question 2

The SI unit for current or amount of charge per second, or how many electrons are flowing past a particular point in the current in 1 second

Answer 2

Ampere (Amp)

Question 3

The SI unit of measurement for frequency; 1 ___ is defined as 1 cycle per second

Answer 3

Hertz

Question 4

Acts in the same manner as a fuse. If the current flowing through it rises above a certain level, the ______ flips its internal switch to open the circuit and stop the electric flow.

Answer 4

Circuit breaker

Question 5

A metal or other substance with electrons that are free to produce a current

Answer 5

Conductor

Question 6

One of three forms of electrification of an object; occurs by touching the object so that the charge transfers to it

Answer 6

Contact

Question 7

The SI unit equal to the electrical charge of 6.25 x 10^18 electrons

Answer 7

Coulomb (C)

Question 8

Formula for finding C

Answer 8

C = J/V

Question 9

SI unit for energy or work

Answer 9

Joule (J)

Question 10

Formula for finding J

Answer 10

J = V(C)

Question 11

SI unit of electromotive force; measures the different potential energy that exists between one point and the other

Answer 11

Volts (V)

Question 12

Formula for finding V

Answer 12

V=J/C

Question 13

Measures the energy potential that a given circuit can provide

Answer 13

Volts

Question 14

The unit of measurement for electric potential; the difference in electric potential between two points.

Answer 14

Voltage

Question 15

Measures how much “pressure” there is in an electric circuit.

Answer 15

Voltage

Question 16

The [higher/lower] the voltage, the more electrical current will flow in the circuit.

Answer 16

Higher

Question 17

The amount of energy (in Joules) that an electrical device (such as a light) is burning per second that it’s running

Answer 17

Watts (W)

Question 18

1 ___ = 1 Joule per second

Answer 18

Watt

Question 19

A statement in physics: the force of attraction or repulsion acting along a straight line between two electric charges is directly proportional to the product of the charges and inversely to the square of the distance between them

Answer 19

Coulomb’s Law

Question 20

Ihe intensity of electromagnetic radiation (I.E. light or x-rays) diminishes by a factor of the square of the distance from its source

Answer 20

Inverse square law

Question 21

Symbolized by (I) and measured in amps (A). It’s the quantity of electrons (“electrical charge”) flowing past a point in a circuit over a given time

Answer 21

Current

Question 22

The type of current that flows in only one direction; the current produced by batteries

Answer 22

Direct current

Question 23

The closed pathway of an electric current.

Answer 23

Electric circuit

Question 24

Potential energy per unit charge. In a battery, for example, many electrons are crowded together at the negative battery terminal. The potential is the difference between the energy per charge at the negative end and the energy per charge at the positive end

Answer 24

Electric potential

Question 25

The principles of electrical charges in motion

Answer 25

Electrodynamics

Question 26

The principles of nonmoving electrical charges

Answer 26

Electrostatics

Question 27

A section of special wire, usually encased in glass, that quickly melts if the current flowing through it rises too high

Answer 27

Fuse

Question 28

Something that is able to absorb electrical charges

Answer 28

Ground

Question 29

A process of connecting an electrical device to the earth using a conductor

Answer 29

Grounding

Question 30

Any charged object can be neutralized if it is grounded as a ____ charged object will take on electrons from the earth and ____ charged objects will give off electrons to the earth until it is neutrally charged

Answer 30

positively; negatively

Question 31

The condition of an object that has gained a charge through friction, contact, or induction

Answer 31

Electrification

Question 32

Three modes in which objects can be electrified

Answer 32

friction, contact, induction

Question 33

Electrons are rubbed away from one object and deposited on another (shuffling your feet on carpet)

Answer 33

Friction

Question 34

When a charged object touches an uncharged object which then acquires the same charge (a shock when your finger touches a doorknob)

Answer 34

Contact

Question 35

Happens when an uncharged metallic object experiences a shift in electrons when it is brought into the electric field of a charged object

Answer 35

Induction

Question 36

A substance that does not conduct electric current because its electrons are bound within the molecules and cannot freely move

Answer 36

Insulators

Question 37

The SI unit for resistance, shown by the Greek letter omega

Answer 37

Ohm

Question 38

The ability of an element in a circuit to resist the flow of electricity by reducing or impeding it

Answer 38

Resistance

Question 39

The amount of resistance of a conductor depends on four things:

Answer 39

Material, length, cross- sectional area, temperature

Question 40

Resistance is directly related to the ___ of the conductor

Answer 40

length

Question 41

___ materials have virtually no free electrons (insulators) unlike good conducting materials (metals)

Answer 41

Resistant

Question 42

A conductor with a large ____ will have a lower resistance because there is Aa greater external surface area on which the electrons can travel

Answer 42

cross-sectional area

Question 43

In metallic conductors, resistance is directly proportional to ____

Answer 43

temperature

Question 44

The energy of an object in motion

Answer 44

Kinetic energy (KE)

Question 45

The energy that is possessed by an object due to its motion or due to its position.

Answer 45

Mechanical energy

Question 46

____ can be either kinetic energy (energy of motion) or potential energy (stored energy of position)

Answer 46

Mechanical energy

Question 47

Stored energy

Answer 47

potential energy

Question 48

The force of attraction between all the particles of a nucleus, both protons and neutrons

Answer 48

strong nuclear force

Question 49

the energy contained within a system that is responsible for its temperature. Heat is the flow of _____

Answer 49

thermal energy

Question 50

the force needed to accelerate one kilogram of mass at the rate of one meter per second squared

Answer 50

Newton

Question 51

Like charges ___, unlike charges ___

Answer 51

repel; attract

Question 52

Reside only on the outside surface of conductors

Answer 52

Electric charges

Question 53

The concentration of charges on a curved surface is ____ where the curvature is greatest

Answer 53

greatest

Question 54

Only ___ charges (electrons) are free to move

Answer 54

negative

Question 55

If a radiographer stands 5 m from an X-ray tube and the exposure rate of 4 mR/hr, what will the intensity (exposure rate) be @ 10 m from the X-ray tube? A) 1 mR/hr B) 16 mR/hr

Answer 55

A

Question 56

The [x] states that the intensity of the x-ray beam is inversely proportional to the square of the distance between the source of the x-rays and the object

Answer 56

Inverse Square Law

Question 57

To apply the inverse square law, one must know:

Answer 57

Two distances and one intensity

Question 57

T/F: The number of electrons in a Coulomb can be expressed numerically as 6.022X1023

Answer 57

False

Question 58

T/F: An "open circuit" allows for the free flow of electrons without resistance or stoppage

Answer 58

False

Question 59

Hertz is the SI unit of measurement for frequency (abbreviated Hz); 1 Hz is defined as:

Answer 59

1 cycle per second

Question 60

T/F: The free flow of electrons across a conductor is referred to as Voltage

Answer 60

False

Question 61

mass of the object multiplied by its velocity

Answer 61

Momentum

Question 62

mass of the object multiplied by the acceleration.

Answer 62

Force

Question 63

subtract the initial velocity of an object from its final velocity and dividing that value by the time used.

Answer 63

Acceleration

Question 64

distance traveled, divided by the time necessary to cover that distance

Answer 64

Velocity

Question 65

another name for velocity

Answer 65

Speed

Question 66

rate of change of velocity with distance

Answer 66

Acceleration

Question 67

resistance to a change in motion

Answer 67

Inertia

Question 68

SI unit of measure for length

Answer 68

Meter

Question 69

SI unit of measure for time

Answer 69

Second

Question 70

Unit of energy

Answer 70

joule

Question 71

unit of electric potential

Answer 71

kVp

Question 72

fundamental unit of force

Answer 72

Newton

Question 73

unit of measurement that is the same for all systems

Answer 73

second

Question 74

Matter is composed of all of the following except: -Mass -Molecules -Ion pairs -Atoms

Answer 74

Ion pairs

Question 75

Energy in a stored state

Answer 75

potential energy

Question 76

What standard system of units has been adopted by all countries and is used in all branches of science?

Answer 76

International System of Units (SI)

Question 77

When did Wilhelm Conrad Roentgen discover x-rays?

Answer 77

November 8th, 1895

Question 78

What is the SI unit for mass?

Answer 78

kilogram

Question 79

When objects gain either a net positive or a net negative charge

Answer 79

Electrification

Question 80

Coulombs/second

Answer 80

Amperes

Question 81

Formula for resistance:

Answer 81

R (resistance)= V (voltage)/I (current)