Lesson 5 Flashcards
Resistance to the flow of electricity is measured in ? .
Select one:
a. amperes
b. ohms
c. volts
d. watts
b. ohms
An electrical shock occurs when the ? becomes a part of the electric circuit.
Select one:
a. body
b. hand tools
c. live line tools
d. worker’s clothing
a. body
It is important to understand three things about electricity in order to work with it safely: how parts of the human body react to it, how it can be directed, and how it ? .
Select one:
a. acts
b. builds current flow
c. creates heat
d. grounds itself
a. acts
One of the factors that determine the resistance of a material is the ? of the substance.
Select one:
a. age
b. temperature
c. viscosity
d. weight
b. temperature
The hand-to-hand resistance of a Qualified Electrical Worker working on a circuit is 5,000 ohms. The circuit voltage is 480 volts. The amount of current that would flow in the worker’s body if he becomes part of the circuit is ? .
Select one:
a. 66 mA
b. 86 mA
c. 96 mA
d. 106 mA
c. 96 mA
One way for a person to receive an electrical shock normally occurs when he or she makes contact with one part of an energized circuit and the ground.
Select one:
True
False
True
An outside electric current with as little as ? can upset the rhythmic, coordinated beating of the heart by disturbing the nerve impulses.
Select one:
a. 75 mA
b. 90 mA
c. 100 mA
d. 112 mA
a. 75 mA
When it is dry, the outer layer of skin may have a resistance of several ? , but when it is moist, there is a radical drop in resistance.
Select one:
a. hundred ohms
b. thousand ohms
c. hundred thousand ohms
d. million ohms
b. thousand ohms
The skin has a “breakdown” voltage at which point it is “punctured,” leaving only the lower resistance body tissue to impede the flow of current. This voltage will vary with the individual, but is in the area of ? .
Select one:
a. 120 V
b. 240 V
c. 600 V
d. 13,200 V
c. 600 V
Electric shock can cause loss of ? , resulting in the inability to let go of an electrical conductor.
Select one:
a. brain function
b. heart function
c. lung/breathing function
d. muscular control
d. muscular control
A severe shock can cause considerably more damage to the body than ? .
Select one:
a. a car accident
b. a fall from a pole
c. from a severe pinch point
d. is visible
d. is visible
Head protection for workers exposed to electrical shock must be designed to provide protection against an accidental electrical contact.
Select one:
True
False
True
The “let-go” threshold for a man receiving an electrical shock is between 9 and ? .
Select one:
a. 30 mA
b. 60 mA
c. 80 mA
d. 100 mA
a. 30 mA
The possibility of cardiac arrest, severe burns, and death can occur when an electrical shock of ? occurs.
Select one:
a. 2,000 mA
b. 4,000 mA
c. 7,000 mA
d. 10,000 mA
d. 10,000 mA
The ? part of an electrical arc is caused by the pressure developed by the near-instantaneous heating of the air surrounding the arc and from the expansion of the metal as it is vaporized.
Select one:
a. blast
b. incendiary
c. percussion
d. shock wave
a. blast
