Deck 17: Electrical Hazards

Question 1

3.Which of the following hazardous locations classifications is most hazardous?

A)Class I,Division 2
B)Class II,Division 1
C)Class II,Division 2
D)Class III,Division 2

Answer 1

B

Question 2

14.What is the principal disadvantage of relying upon defibrillation devices to save the lives of electrocution victims?

Answer 2

A defibrillation device is rarely available soon enough to save the life of an electrocution victim.

Question 3

6.Which of the following circuits causes the most electrocutions annually in the United States?

A)20 volt
B)110 volt
C)220 volt
D)440 volt

Answer 3

B

Question 4

10.The presence of wounds in the skin can result in much higher current flow if electrical contact is made where the skin is broken.

Question 5

17.Which of the following is the least important factor in determining whether an electrocution will take place?

A)dampness at the point of contact
B)body weight of the individual
C)path of current through the body
D)wounds in the skin where contact is made

Question 6

5.A common household circuit rated at 15 amps can carry approximately how many times as much current passing through the heart muscle as is required to produce heart fibrillation?

A)twice as much
B)five times as much
C)ten times as much
D)200 times as much

Question 7

20.Fibrillation is due primarily to

A)high voltage
B)high current
C)direct current
D)alternating current

Question 8

18.Explain why electric shock can arrest the heart.

Question 9

19.Fibrillation can sometimes be stopped by controlled electric shocks to reestablish the heart's natural rhythms.

Question 10

13.Public utility companies regulate the oscillation of alternating current to 60 hertz because this frequency has been found to be the most safe for exposure to the human heart muscle and thus to prevent most electrocutions.

Question 11

8.A certain string of Christmas tree lights has twenty bulbs,each rated at 3 watts.If there is no ground fault,how much current flows through the hot wire at the receptacle plug? Show calculations.How much flows through the neutral? Would the current flow likely be fatal if all of the current flowing through the hot wire would pass through a person's heart muscle?

Question 12

4."Reversed polarity" means that

A)the neutral and equipment ground are reversed
B)the hot and equipment ground are reversed
C)the hot and neutral are reversed
D)none of the above

Question 13

12.Even body perspiration can provide the dampness that can make electrical contact fatal.

Question 14

11.The most important factor in determining whether a person will be electrocuted when exposed to electric shock is whether the person has an inherent physical resistance to electrical hazards.

Question 15

9.Ordinary household 110v circuits are capable of electric shock but such shocks can be assumed to not be fatal.

Question 16

7.When one probe of a circuit tester contacts a hot wire and the other probe a neutral wire,

A)the bulb will light
B)a fuse or breaker or the tester bulb will blow
C)the tester will be electrocuted
D)OSHA will issue a citation

Question 17

2.A paint spray booth in which flammable paints are used would be classified as

A)Class I,Division 1
B)Class I,Division 2
C)Class II,Division 1
D)Class II,Division 2

Question 18

16.Which of the following circuit voltage levels results in the most frequent occurrence of electrocution?

A)6v
B)12v
C)110v
D)220v

Question 19

1.Weatherproof electrical outlets as seen installed on decks and patios are

A)approved for Class I,Division 1
B)approved for Class I,Division 2
C)approved for Class III,Division 2
D)are not approved for hazardous locations

Question 20

15.Which of the following circuit voltage levels results in the most frequent occurrence of electrocution?

A)110v
B)220v
C)440v
D)7800v

Question 21

26.What is the full name represented by the abbreviation GFCI?

Question 22

27.A GFCI is a

A)ground-fault current interruptor
B)ground-fault circuit interruptor
C)ground-fault current inhibitor
D)ground-fault circuit inhibitor

Question 23

37.The diagram illustrates what type of tester?

Question 24

38.The diagram illustrates what type of tester?

Question 25

36.The diagram illustrates what type of tester?

Question 26

40.A typical 120-volt household circuit delivers 350 watts of power to an appliance,and another 10 watts of power are consumed by the circuit.There is no ground fault.a.How much current is carried by the hot wire?

Question 27

A typical 110-volt household circuit delivers 200 watts of power to an appliance,and another 20 watts of power are consumed by the circuit.There is no ground fault.The hot wire carries a 2 amp current.
a.How much current is carried by the neutral?
b. How much current is carried by the ground?
c. What is the resistance of the circuit?

Question 28

21.The standard frequency for alternating current is

A)20 Hz
B)60 Hz
C)110 Hz
D)220 Hz

Question 29

24.Perspiration can lower skin resistance to electricity by as much as a factor of

A)2
B)10
C)100
D)200

Question 30

34.When a receptacle wiring tester is plugged into a receptacle that has an open ground

A)no indicators will light
B)one indicator will light
C)two indicators will light
D)three indicators will light

Question 31

30.A loose or corroded connection in the neutral circuit will cause

A)a decrease in resistance and an increase in voltage drop
B)an increase in resistance and a decrease in voltage drop
C)a decrease in resistance and a decrease in voltage drop
D)an increase in resistance and an increase in voltage drop

Question 32

32.When a receptacle wiring tester is plugged into a receptacle that is wired correctly

A)no indicators will light
B)one indicator will light
C)two indicators will light
D)three indicators will light

Question 33

23.The current drawn by a 60-watt table lamp circuit is approximately

A)1/2 amp
B)1 amp
C)5 amp
D)15 amp

Question 34

33.When a receptacle wiring tester is plugged into a receptacle that has reversed polarity

A)no indicators will light
B)one indicator will light
C)two indicators will light
D)three indicators will light

Question 35

28.When the ground-fault current flows through a person's body,the 15-amp circuit breaker in the circuit will throw and protect the worker from electrocution.

Question 36

22.The peak voltage for an ordinary household A.C.circuit is approximately

A)60
B)110 volts
C)150 volts
D)220 volts

Question 37

31.When equipment is connected to a circuit having an "open ground," but equipped with a GFCI

A)a fuse will blow or a breaker will be tripped
B)the equipment will not operate
C)the GFCI will be tripped
D)the equipment will operate normally

Question 38

35.In which of the following testers are you likely to find a battery?

A)receptacle wiring tester
B)circuit tester
C)continuity tester
D)none of the above

Question 39

29."Double insulation" is permitted in lieu of

A)grounding
B)circuit breakers
C)fuses
D)GFCIs

Question 40

39.An alternative to GFCIs on construction sites is

A)the use of anti-two blocking devices
B)an assured equipment grounding program
C)double insulation on all tools
D)Underwriters Laboratories or Factory Mutual Engg approval

Question 41

44.Explain the difference between an ordinary circuit breaker and a GFCI.Include in your explanation what the letters "GFCI" literally represent.

Question 42

Ground wire - this is a non-current-carrying conductor and is a safety feature for bringing the case and other exposed parts of the equipment to ground potential in case of a short.The short will cause a large flow of current through the circuit,which should trip the breaker and cause current flow to cease.(sometimes called the groundING conductor)

Question 43

56.Which of the following will result in the largest arc flash?

A)one second of power
B)one pound of TNT
C)20 cycles of power exposure
D)one gram of TNT

Question 44

52.The release of arc flash energy is measured in all of the following except:

A)megawatts
B)joules
C)megajoules
D)grams of TNT

Question 45

48.Explain the term "fibrillation" and how it relates to the field of safety.

Question 46

46.Write a brief paragraph on the physiology of electric shock.Include explanations of organs affected,electric current levels that are dangerous,conditions that aggravate the problem,and why.

Question 47

50.Electrical energy is measured in

A)amperes
B)volts
C)watts
D)joules

Question 48

42.Which of the following miswiring conditions is likely to cause a piece of equipment to continue to operate even after it is turned off?

A)reversed polarity
B)ground jumped to neutral
C)ground and neutral reversed
D)open ground

Question 49

47.A certain string of Christmas tree lights has 100 bulbs,each rated at 500 milliwatts.The string of lights plugs into a standard 120 volt circuit.Assume that there is no ground fault.Calculate the current flow through the hot wire.Calculate the current flow through the neutral.

Question 50

41.Explain the limitations of the phrase "electricity follows the path of least resistance," as it pertains to electrocution hazards.

Question 51

49.Show calculations to determine the power of the arc flash that would be generated from an accidental fault in 480-volt circuit that is capable of delivering a current of 10,000 amperes.

Question 52

43.Calculate the maximum total resistance below which a 120 volt circuit will trip a 15 amp breaker.Show your work.

Question 53

55.To determine the energy released in an arc flash the power in megawatts is multiplied by the

A)current flow in amperes
B)voltage measured in megavolts
C)the force in newtons
D)the duration in seconds

Question 54

51.The release of arc flash energy is measured in

A)millivolts
B)megawatts
C)megajoules
D)volt-newtons