Deck 12: Electric Current and Related Variables in Engineering

Question 1

The law that states that at any given time, the sum of the currents entering a node must equal the sum of the currents leaving the node is know as

A)Kirchoff's current law
B)Kirchoff's voltage law
C)Ohm's law
D)Coulomb's law

Answer 1

A

Question 2

The flow of electric charge that periodically reverses direction that is typically produced by rotating generators is known as

A)ac current.
B)dc current.
C)ac/dc current.
D)omni directional current.

Answer 2

A

Question 3

The flow of electric charge that occurs in one direction that is typically produced by batteries is known as

A)ac current.
B)dc current.
C)ac/dc current.
D)unidirectional current.

Answer 3

B

Question 4

In SI units, the unit of charge is the coulomb (C).

Question 5

The basic law of electric charges states that unlike charges attract each other while like charges repel.

Question 6

Which of the following batteries is an example of a primary cell?

A)Nickel-cadmium (NiCd) also known as "nicad"
B)Nickel-metal hydride (NiMH)
C)Alkaline
D)Lead acid

Question 7

The flow of charge will occur when the two bodies are connected by an electrical conductor such as a copper wire.The flow of electric charge is called electric current.

Question 8

Which subatomic particle has no charge?

A)Proton
B)Neutron
C)Electron
D)Ion

Question 9

Which subatomic particle has a negative charge?

A)Proton
B)Neutron
C)Electron
D)Ion

Question 10

Primary cells are batteries that can be recharged while secondary cells are batteries that cannot be recharged.

Question 11

Every engineer needs to understand the fundamentals of electricity and magnetism.

Question 12

In all batteries, electricity is produced by

A)light
B)heat
C)a chemical reaction
D)all of the above

Question 13

Which subatomic particle has a positive charge?

A)Proton
B)Neutron
C)Electron
D)Ion

Question 14

Electric current is a fundamental dimension.

Question 15

The amount of work required to move charge between two points is represented by

A)electric current
B)resistance
C)voltage
D)energy

Question 16

In general, there are two ways in which the sun's energy is converted into electricity:

A)photovoltaic and photothermal
B)photovoltaic and photochemical
C)photovoltaic and photosynthetic
D)none of the above

Question 17

Voltage is sometime referred to as emf.What does emf stand for?

A)Electromagnetic frequency
B)Electromotive frequency
C)Electromagnetic force
D)Electromotive force

Question 18

An electrical circuit refers to the combination of various electrical components that are connected together.

Question 19

One coulomb is defined as the amount of charge that passes a point in a wire in 1 second when a current of 1 ampere is flowing through the wire.

Question 20

The SI unit for electric current is

A)amperes
B)electrons per second
C)coulombs
D)watts

Question 21

In certain circuits, if one of the elements fails, that failure prevents the current from flowing through other elements in the circuit; thus the entire circuit fails.This type of circuit is a

A)parallel circuit
B)series circuit
C)none of the above

Question 22

A numbering system that describes the size of an electric conductor is AWG.What does AWG stand for?

A)American Wire Gage
B)Association of Wire Gages
C)Atlas of Wire Gages
D)All Wire Gages

Question 23

Ohm's law describes the relationship between voltage, resistance, and current.Which of these is Ohm's law?

A)
B)
C)
D)

Question 24

Electrical resistance is a fundamental dimension.

Question 25

Most indoor fluorescent light fixtures contain two or three 40-watt bulbs each.If a classroom has 15 fluorescent light fixtures, each with three 40-watt bulbs, how much does it cost to leave the lights on for a two-hour class? Assume the electric company charges approximately 10 cents per kilowatt-hour.

Question 26

Electrical components that store energy on two oppositely charged electrodes, rather than through a chemical reaction are known as

A)batteries
B)inductors
C)transistors
D)capacitors

Question 27

In lighting design, a variable called CRI is often used.What does CRI stand for?

A)Color Repeatability Index
B)Color Rendition Index
C)Capacitive-Resistive Index
D)none of the above

Question 28

The electrical resistance of a material does not vary with temperature.

Question 29

A common unit of illumination intensity is called a footcandle and is equal to

A)the amount of light one foot away from a candle.
B)the amount of light from a one-foot long candle.
C)one lumen distributed over an area of 1-square-foot.
D)none of the above

Question 30

According to a light bulb manufacturer, its 75 W CFL floodlight consumes 25 W and produces 1500 lumens.What is the efficacy of the floodlight?

Question 31

How many kW-hour is consumed by a TV set that uses 250 watts when it is left on for 4 hours?

A)250
B)1000
C)1
D)0.25

Question 32

The ratio of the diameter of No.1 AWG wire to No.2 is

A)1.25
B)1.5
C)2.0
D)1.12

Question 33

the amount of light emitted by a lamp is expressed in lumens.

Question 34

Some of the factors that engineers consider when selecting a motor for an application are:

A)motor type and speed (rpm).
B)motor performance and efficiency.
C)cost, life expectancy, and noise level.
D)maintenance and service requirements.
E)all of the above

Question 35

The distribution of light on a horizontal surface is known as

A)luminescence
B)luminosity
C)illuminescence
D)illumination

Question 36

When it comes to wire size, the larger the gage number the larger the wire diameter.

Question 37

Some materials exhibit near-zero resistance at very low temperatures.This behavior is called

A)infra-resistance
B)anti-resistance
C)semiconductivity
D)superconductivity

Question 38

Capacitors are used for

A)energy storage
B)electronic filters
C)timing elements
D)all of the above

Question 39

The ratio of how much light is produced by a lamp (in lumens) to how much energy is consumed by the lamp (in watts) is known as

A)efficacy
B)efficiency
C)illumination cost
D)energy cost

Question 40

One kilowatt hour represents the amount of power consumed during 1 hour by a device that uses one kilowatt (kW).