NCCER Electrical Level 1 Module 26105-20 Exam Questions and Answers 100% Correct
Graded A+ 2026/27
Double insulated/ungrounded tools - Electrical tools that are constructed so that the case is
insulated from electrical energy. The case is made of a nonconductive material
Ground Fault Circuit Interrupter (GFCI) - A protective device that functions to de-
energize a circuit or portion thereof within an established period of time when a current to
ground exceeds some predetermined value. This value is less than that required to operate the
over current protective device of the supply circuit.
4 most life threatening hazards on a construction site - -Falls
-Electric shock/arc burns
-Being crushed by falling material
-Being struck by flying or moving equipment
electrical current - movement of electrons
example of conductors - silver, copper, steel, aluminimum, human body
Effect of 5mA shock - slight shock, involuntary movement
Effect of 6mA-30mA - painful shock, loss of muscle control
, Effect of 50mA- 150mA - Extreme pain, respiratory arrestm severe muscular contractions,
death possible
Effect of 1,000 mA - 4,300mA - VFIB, Nerve damage, typically results in death
main cause of electrical accidents - contact with conductors
second cause of electrical accidents - portable electrically operated hand tools- frame or
case of tool is energized
most electrocution deaths occur with__ - low voltages due to the frequency of contact
What is the resistance of the human body? - 1,000 ohms and current of 50mA can cause
death
What voltage needs protection - 50V or higher
What are 3 ways shock occurs? - person comes in contact with:
-both wires of the electric circuit
-one wire of the electric circuit and the ground
-metallic part that has become live while person is in contact with ground
Graded A+ 2026/27
Double insulated/ungrounded tools - Electrical tools that are constructed so that the case is
insulated from electrical energy. The case is made of a nonconductive material
Ground Fault Circuit Interrupter (GFCI) - A protective device that functions to de-
energize a circuit or portion thereof within an established period of time when a current to
ground exceeds some predetermined value. This value is less than that required to operate the
over current protective device of the supply circuit.
4 most life threatening hazards on a construction site - -Falls
-Electric shock/arc burns
-Being crushed by falling material
-Being struck by flying or moving equipment
electrical current - movement of electrons
example of conductors - silver, copper, steel, aluminimum, human body
Effect of 5mA shock - slight shock, involuntary movement
Effect of 6mA-30mA - painful shock, loss of muscle control
, Effect of 50mA- 150mA - Extreme pain, respiratory arrestm severe muscular contractions,
death possible
Effect of 1,000 mA - 4,300mA - VFIB, Nerve damage, typically results in death
main cause of electrical accidents - contact with conductors
second cause of electrical accidents - portable electrically operated hand tools- frame or
case of tool is energized
most electrocution deaths occur with__ - low voltages due to the frequency of contact
What is the resistance of the human body? - 1,000 ohms and current of 50mA can cause
death
What voltage needs protection - 50V or higher
What are 3 ways shock occurs? - person comes in contact with:
-both wires of the electric circuit
-one wire of the electric circuit and the ground
-metallic part that has become live while person is in contact with ground
