ELECTRICAL AND MECHANICAL TEST #3 QUESTIONS AND ANSWERS | EXAM PREP & PRACTICE TEST 2026/2027

ELECTRICAL AND MECHANICAL TEST #3 QUESTIONS AND ANSWERS | EXAM PREP & PRACTICE
TEST 2026/2027



Chapter 20 - Electrical Principles, Tools, and Safety - ANS ✔✔



____________ is anything that has mass and occupies space.

Note: All has electrical properties

Note: Solid, liquid, gas - ANS ✔✔Matter



An _______ is the smallest particle that an element can be reduced to and still maintain the
properties of that element.

Note: Positive charge- excess protons

Note: Negative charge- excess electron - ANS ✔✔atom



The ___________ in an atom are arranged in shells at various distances from the nucleus
according to the amount of energy they have - ANS ✔✔electrons



__________________ is the outermost shell of an atom. The electrons in the valence shell are
important because they can be used to produce an electric current flow - ANS ✔✔Valence shell



________________________ is a material that has very little resistance and allows electrons to
easily move through. Examples: silver**, copper, gold, aluminum, iron - ANS ✔✔Conductor



______________________ is any material that has a very high resistance and resists the flow of
electrons. Examples: glass, rubber, plastic, paper - ANS ✔✔Insulator



_______________________ is materials that has conductivity between conductor and insulator.
Examples: carbon, silicon - ANS ✔✔Semiconductor

,In a ____________________, an outside force can be applied to force the atom to lose or gain
valence electrons. - ANS ✔✔conductor atom



____________________________are moved by force: chemical reaction, friction, pressure,
heat, light, or a magnetic field - ANS ✔✔Electrons



____________________________ produce electricity (AC Power) when magnetic lines of force
are cut by a rotating wire coil.



Note: The stronger the magnetic field and/or the faster the rotation, the higher the voltage -
ANS ✔✔Power Plant Generators



_____________________________________is an electric device that uses electro-magnetism
to change (step-up or stepdown) AC voltage from one level to another. - ANS ✔✔transformer



Power plant transformers step-up voltage to____________________________volts or
____________ Kilovolts for the efficient distribution of electricity. - ANS ✔✔- 240,000 V

- (240 KV)



Electrical service entrances can be either ___________ or __________. - ANS ✔✔overhead or
underground



_____________________ is an electrical device containing fuses or circuit breakers for
protecting the individual circuits of a residence and serves as a means of disconnecting the
entire residence from the distribution system.

Note:

-Easily Accessible

-Wall mounted

, -Typically found in basements, utility rooms, attached garages - ANS ✔✔A service panel



A _________________ is a complete path for current to take and includes electrical control
devices, circuit protection, conductors and loads. - ANS ✔✔circuit



______________ the wires in a circuit can find a short cut, bypassing the load. Voltage
increases, causing wires to heat up. - ANS ✔✔Short circuit



______________________ protects occupants by providing a safe pathway for unwanted
electricity that may otherwise create a hazard - ANS ✔✔Grounding



What are the two main types of grounding for residences? - ANS ✔✔-Water pipe grounding

-electrode grounding



_________________ safely grounds any devices attached to a system or plugged into
receptacles inside a home

Note: Human body is a conductor - ANS ✔✔Equipment grounding



________________ is an electric overcurrent protection device used to limit the rate of current
flow in a circuit. - ANS ✔✔Fuse



What are the three types of fuses? - ANS ✔✔-Plug

-Cartridge

-Blade



___________________- is an overcurrent protection device with a mechanical mechanism that
may manually or automatically open a circuit when an overload condition or short circuit
occurs.