semifinal Flashcards

1
Q

if the frequency of a series RL circuit is increased, the total current will ___

A

decrease

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2
Q

the total opposition to current flow in an RL circuit is expressed in a quantity called _____

A

impedance

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3
Q

if the frequency of a parallel rc circuit is increased, the total currents will _____

A

increase

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4
Q

Which is the most widely used semiconductor material

A

silicon

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5
Q

when voltage is applied to a diode the action occurring in the ____ region either block current flow or passes current

A

depletion

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6
Q

A shorted diode is indicated by low resistance in _____

A

both direction

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7
Q

The primary purpose of a zener diode is to last as a _____ either by itself or in conjunction with other semiconductor devices

A

voltage regulator

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8
Q

A diode will conduct normal current when the _____ is positive with respect to the _____

A

anode

cathode

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9
Q

discs are used almost exclusively as _____ devices

A

triggering

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10
Q

to test as SCR with an ohmmeter connect the _______ led to the anode and the ______ lead to the cathode

A

positive

negative

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11
Q

The fastest way to turn off an SCR is by

A

zero biasing it

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12
Q

The greatest advantage of a photoemissive device is its

A

speed of operation

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13
Q

oscillators

A

in-phase feedback is called positive feedback

an oscillator is a device that converts dc to ac

an oscillator is an amplifier that supplies its own input signal

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14
Q

You are testing an SCR with an OHMMETER. You have connected the positive output lead of the meter to the cathode and the negative lead to the anode. The ohmmeter indicates continuity through the SCR. You should conclude the SCR us _____

A

shorted

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15
Q

The primary function of an octogenarian-coupler is to provide electrical ____ between inputs and outputs, especially in the presence of high voltages

A

isolation

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16
Q

A proprietary supervising station is under ______ and must be located on _____

A

single ownership

property owned by the owner of the station

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17
Q

A ______ switch is a supervisory switch

A

Room Temperature
Valve tamper
water level

18
Q

A short circuit on a fire alarm initiating device circuit causes a _____ signal

A

trouble

19
Q

a firestopping material that expands when heated is referred to as

A

intumescent

20
Q

interconnected fire alarm systems can be connected together by using

A

electrical contacts listed for the connected load

a lifted gateway

data communications circuits dedicated to the fire alarm system or shared with other building systems

21
Q

in combination systems, fire alarm signals must be

A

different from other NON-FIRE alarm signals

22
Q

Which sling hitch consists of two or more straight slings of the same type that bring together mulitplelifting points to a single hoisting point?

A

bridle

23
Q

A _____ is several piece of yarn or wire twisted spirally around an axis

A

strand

24
Q

_____ limits for rope are established by dividing the breaking strength by the safety factor

A

safe working load

25
Q

______ describes “tackle” as it relates to rigging and lifting applications

A

the combination of ropes and accessories arranged with blocks

26
Q

For maximum accuracy, a torque wrench should only be used for ranges between ___ and ___ percent of its maximum rated value

A

30/80

27
Q

______ force is created by the spring action of a bolt

A

Clamping

28
Q

The proper use of a torque wrench is

A

pulling motion toward the operator

29
Q

What is the best way to protect against voltage spikes in a DC circuit.

A

Add a diode across the play coil

30
Q

non power-limited fire alarm systems have a max operating voltage

A

600 volts

31
Q

photo-operate devices fall into 3 categories.

A

photovoltaic
photoconductive
photoemissive

32
Q

The main difference between an LED and LCD. LEDs ____ light while LCDs ____ light

A

emit

control

33
Q

The amount of _____ produced by a solar cell is determined by the surface area of the cell

A

current

34
Q

three advantages of photo operated devices

A

no moving parts to wear out

quick reaction and response time

no bouncing contacts

35
Q

5 steps for processes involved in a complete power supply system

A
transformer
rectifier
filter
voltage regulator
voltage divider
36
Q

3 advantages of fiber optic cable over copper

A

eliminate electrical and magnetic field interference

greater data capacity for longer runs

high data security

37
Q

manual fire alarm boxes must be mounted no higher than ____ inches for front reach applications

A

48

38
Q

a 3-transformer closed cell bank will supply about ____ percent more power to a load than a two transformer open delta bank

A

25%

39
Q

Four primary functions of fire alarm systems

A

containment
detection
suppression
notification

40
Q

manual fire alarm boxes must be installed within _____ feet of a doorway

A

5

41
Q

find the current gain for a transistor with collector current of 60 milliamps and a base current of 0.4 milliamps.

A

B= Ic/Is