COMPREHENSIVE EXAM 2026 TESTED
QUESTIONS WITH SOLUTIONS GRADED A+
◉ Name some advantages of Extra low voltage switching systems over a
120/240V switching system? Answer: 1) Control wiring, switching and
relays only need a 24V rating 2) Small current is required to operate the
ELV (extra low voltage) coils. 3) Fewer power losses in the control
circuit
◉ What is the basic function of a relay in an ELV (extra low voltage)
system? Answer: The relay will have two 24V coils, joined at a common
terminal. The coils can move the armature. When the ON coil is
energized, the magnetic field will move the armature in a linear
direction. The armature is latched with a mechanical latch and the
contacts remain in the CLOSED position.
◉ Explain a rectifying diode. Answer: Three wire ELV system will use a
rectifying diode. This is a simple device that allows little pulses of
current to flow to the coil in one direction only. This is done because
there needs to be protection for the relay if a momentary contact switch
is stuck or held in the ON or OFF position.
, ◉ True or False: Extra low voltage circuits always come equipped with
pilot lights. Answer: False. Only some are equipped, while other circuits
don't always require them.
◉ True or False: Pilot lights relays are an extra set of contacts that close
when the ON coil is energized to turn on a light. Answer: True.
◉ List the types of meters used in the Electrician trade. Answer: 1)
Voltmeter 2) Ammeters 3) Ohmmeters 4) Meghommeters 5) Wattmeters
6) Multi-meters
◉ Tell me which meters are connected in series, which ones are
connected in parallel, and which ones can use a combination
connection? Answer: 1) Voltmeter - Parallel 2) Ammeter - Series 3)
Ohmeters - both applications 4) Meghommeters - both applications 5)
Wattmeters -current coils in series, potential coil in parallel 6) Multi-
meters - depends on application of usage
◉ True or False: Intrusion sensing is NOT divided into perimeter
devices and internal devices. They AREN'T used to sense intruders.
Answer: False. They are used for that following application as explained
in the question.
◉ True or False: Magnetic Reed Switches are long metal reeds that are
pulled close by a magnetic force to a nearby magnet. Answer: True. And
this won't help you "reed in fishies" unfortunately.