Midterm Questions Flashcards
The maximum reverse bias voltage a diode can withstand is known as ? voltage.
a. barrier
b. breakdown
c. depletion region
d. peak inverse
d. peak inverse
Since diodes conduct current flow in only one direction, they are commonly used to convert an AC voltage to a(n) ? DC voltage.
a. barrier
b. breakdown.
c. excitation
d. pulsating
d. pulsating
? is the process of converting an AC voltage to a DC voltage.
a. Alternation
b. Conversion
c. Doping
d. Rectification
d.
Rectification
In a zener diode, the reverse breakdown voltage is referred to as ? voltage.
a. barrier
b. breakover
c. peak inverse
d. zener
d. zener
Identify the correct name of the transistor symbol.
A ? has three leads identified as base, collector, and emitter.
a. BJT
b. JFET
c. Triac
a. BJT
The gate lead controls or triggers the SCR.
Select one:
True
False
true
The triac is a half-wave device.
Select one:
True
False
false
A diode that has a high resistance at both polarities is ? .
a.
open
b.
shorted
a. open
A diode that has a low resistance at both polarities is ? .
a.
open
b.
shorted
b. shorted
Capacitive, inductive and ultrasonic are three types of ______ sensors that are based on the sensor’s operating principles.
a. analog
b. contact
c. photoelectric
d. proximity
d. proximity
Sensors that use an NPN transistor to switch DC loads are current-______ devices.
a. sinking
b. sourcing
a. sinking
Current-sinking outputs use the ______ side of the DC output circuit as the switch leg to the load device.
a. negative
b. positive
a. negative
A ______ can be used to protect SSRs from brief voltage spikes.
a. metal-oxide varistor
b. semiconductor fuse
c. zener diode
a. metal-oxide varistor
Intermittent problems or erratic operation with a programmable relay most likely indicates a ______ problem.
a. hardware
b. software
a. hardware
The fault current withstand rating of an MCC is determined by the highest rated device within the MCC.
True or False
False
In corrosive atmospheres, copper buses in MCCs are often coated with ______ to protect the bus from corrosion.
a. carbon
b. tin
c. zinc
b. tin
Reduced voltage starting techniques for DC motors have replaced DC motor drives in many DC motor applications.
True or False
False
Most power distribution systems are designed for huge current fluctuations on their power grid.
True or False
False
In troubleshooting a control circuit, the first step is to verify that ______ are (is) present.
a. control power
b. interlocking contacts
c. overload contacts
a. control power
Troubleshooting control circuits involves using a ______ to analyze the control logic.
a. ladder diagram
b. one-line diagram
c. starter manufacture drawing
d. wiring diagram
a. ladder diagram
Programmed timers’ output contacts change state when the ______ value equals the preset value.
a. accumulated
b. preset
c. time base
a. accumulated
Use the ladder diagram and description as a reference. What is the timer mode for the second timer?
a. 1
b. 4
c. 10
a. 1
