,NEIEP 700 Final Exam – Elevator Systems & Control
Circuits (2026) Q&A | Electrical Engineering
1. When current flows through a relay coil, what is generated that moves the
armature?
A) Magnetic field
B) Heat
C) Static charge
D) Back EMF
Correct Answer: Magnetic field
Rationale: Current through a coil creates a magnetic field, which attracts the
ferromagnetic armature and changes the contact state. Heat and static charge
are secondary effects. Back EMF occurs only when current changes.
2. In elevator schematics, a normally open contact is also called a:
A) Break contact
B) Making contact
C) Transfer contact
D) Closed contact
Correct Answer: Making contact
,Rationale: A normally open contact closes when the relay is energized, thus
“making” the circuit. A break contact is normally closed. These terms are
interchangeable in elevator wiring diagrams.
3. What is the primary purpose of a shading coil in an AC relay?
A) Increase contact pressure
B) Prevent coil burnout
C) Reduce AC hum
D) Speed up relay operation
Correct Answer: Reduce AC hum
Rationale: The shading coil introduces a phase shift in the magnetic field,
preventing the armature from dropping to zero during the AC cycle reversal.
This reduces the characteristic hum and chatter.
4. Suppression diodes are installed across DC relay coils primarily to:
A) Increase holding force
B) Speed up drop-out time
C) Prevent inductive voltage spikes from damaging other components
D) Reduce coil resistance
Correct Answer: Prevent inductive voltage spikes from damaging other
components
, Rationale: When the magnetic field collapses, it can induce a high reverse
voltage (inductive kickback). The diode provides a path for this current,
protecting contacts and transistors.
5. The most common relay type used in modern elevator control systems is the:
A) Plug-type relay
B) Latching relay
C) Reed relay
D) Mercury-wetted relay
Correct Answer: Plug-type relay
Rationale: Plug-type relays are favored for their ease of replacement, reliability,
and standard form factor. They allow quick troubleshooting and minimal
downtime.
6. If a relay coil measures full line voltage directly across its terminals but does
not pull in, the most likely problem is:
A) Shorted turns
B) An open coil
C) Low supply frequency
D) Excessive contact resistance
Correct Answer: An open coil
Circuits (2026) Q&A | Electrical Engineering
1. When current flows through a relay coil, what is generated that moves the
armature?
A) Magnetic field
B) Heat
C) Static charge
D) Back EMF
Correct Answer: Magnetic field
Rationale: Current through a coil creates a magnetic field, which attracts the
ferromagnetic armature and changes the contact state. Heat and static charge
are secondary effects. Back EMF occurs only when current changes.
2. In elevator schematics, a normally open contact is also called a:
A) Break contact
B) Making contact
C) Transfer contact
D) Closed contact
Correct Answer: Making contact
,Rationale: A normally open contact closes when the relay is energized, thus
“making” the circuit. A break contact is normally closed. These terms are
interchangeable in elevator wiring diagrams.
3. What is the primary purpose of a shading coil in an AC relay?
A) Increase contact pressure
B) Prevent coil burnout
C) Reduce AC hum
D) Speed up relay operation
Correct Answer: Reduce AC hum
Rationale: The shading coil introduces a phase shift in the magnetic field,
preventing the armature from dropping to zero during the AC cycle reversal.
This reduces the characteristic hum and chatter.
4. Suppression diodes are installed across DC relay coils primarily to:
A) Increase holding force
B) Speed up drop-out time
C) Prevent inductive voltage spikes from damaging other components
D) Reduce coil resistance
Correct Answer: Prevent inductive voltage spikes from damaging other
components
, Rationale: When the magnetic field collapses, it can induce a high reverse
voltage (inductive kickback). The diode provides a path for this current,
protecting contacts and transistors.
5. The most common relay type used in modern elevator control systems is the:
A) Plug-type relay
B) Latching relay
C) Reed relay
D) Mercury-wetted relay
Correct Answer: Plug-type relay
Rationale: Plug-type relays are favored for their ease of replacement, reliability,
and standard form factor. They allow quick troubleshooting and minimal
downtime.
6. If a relay coil measures full line voltage directly across its terminals but does
not pull in, the most likely problem is:
A) Shorted turns
B) An open coil
C) Low supply frequency
D) Excessive contact resistance
Correct Answer: An open coil
