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Rectifiers and Battery Chargers Part A Flashcards | StudBud
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Rectifiers and Battery Chargers Part A
Rectifiers and Battery Chargers Part A
90 terms
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StudBud Administration
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NWP 2023 Electrical 4th year
Flashcards
90 cards
F
Practice quiz
P
Host live
L
Questions
90
Answers
1
The reference lead is grounded and bonded to the chassis of an oscilloscope
False
True
2
Doping silicon with a trivalent material makes a
P type semi conductor
T type semi conductor
3
What should you do when ohming out a device?
Turn the circuit on to get the ohmic valaue
Turn the circuit off and isolate the device
Just look closely at it and guess
Turn the circuit off but don't disconnect anything
4
The shape of an AC wave form is a sine wave
False
True
5
Heat sinks help the diodes heat up
False
True
6
Forward bias limit of a diode is
The maximum continous reverse current
The rated current or maximum continous forward current
7
A pentavalent material compared to a trivalent material is more negative
True
False
8
Stud mounted are usually up to 100 Amps
True
False
9
The effective value of ac voltage is the heating effect of ac compared to dc on the same resistor
True
False
10
To avoid a short circuit you can isolate either the circuit or scope with an isolation transformer
False
True
11
Atoms join to form a crystal lattice through
glue
covalent bonding
12
The diode in the picture is a
high current diode
low current diode
medium current diode
a resistor
13
The average DC value of a pulsating DC is between the minimum and maximum instantaneous values
False
True
14
Frequency is
The amount of time required for one cycle
How frequent we are told to "draw it out"
The number of sine waves that occur in 1 second
A sequence of events that repeat
15
LED stands for
Light Emitting Diode
Lightning excellent
16
The stud side of the stud mounted diode is
neither the anode or cathode
always the anode
either the anode or cathode
always the cathode
17
A diode that will not allow current to flow because of polarity is called
forward bias
reverse bias
closed
open
18
What does OL mean on a ohmmeter?
Old Lobster
Old lady
Open line or overload
Oh lord
19
A diode only allows current to flow when
diodes never allow current to flow
the anode is negative with respect to the cathode
the anode is positive with respect to the cathode
before we reached the barrier potential
20
An example of a blocking diode is ensuring a fully charged battery doesn't discharge into a partially charged battery
False
True
21
At room temperature, the barrier potential for a silicon PN junction is
0.3 V
0.7V
1 V
a germanium is a flower
22
Which type of diode is used in low voltage switching applications?
isolation
steering or directional
free wheeling
blocking
23
The peak value on a sine wave is also called
The mountain top
the maximum
The curve ratio
the instantaneous value at 45 degrees
24
What will a DC meter read when connected to a AC source
half the AC
twice the AC
whatever the ac source is
Zero
25
The small current that flows in reverse bias of a diode is called
leakage current
there is zero amps that flow
dark current
there is maximum current that flows
26
The forward bias limit is the I
FMax
False
True
27
Choose all the correct: Insulators have
1-3 valence electrons
low electrical resistance
high electrical resistance
5-8 valence electrons
28
The reverse bias limit is also known as (check all that apply)
Peak reverse voltage (PRV)
Driving in reverse
voltage repetitive reverse maximum (VRRM)
peak inverse voltage (PIV)
29
The following is NOT true in direct current
DC is widely used in homes as supply voltage
Polarity does not change
DC has current that only flows in one direction
DC can be pulsating or constant
30
The small current that flows even when a LDR has no light is called
there is max current that flows
leakage current
there is zero amps that flow
dark current
31
The outermost shell of an atom is called
the valence shell
the sharing shell
the seashell
the atmopshere shell
32
Which is NOT a diode current rating
medium
high
extra high
low
33
A dc voltmeter will read
The average DC
There is no DC voltmeters
The peak pulsating DC
AC voltage perfectly
34
Photoconduction is the property of a material that
exhibits higher resistance when exposed to light
exhibits lower resistance when exposed to light
35
When using double-subscript notation, the first letter in the subscript is the reference point.
False
True
36
Before doping the silicon it is an
intrinsic material
clean material
extrinsic material
37
In dc coupled mode on an oscilloscope what is displayed
Ac only
DC only
AC and DC
there is no such thing
38
At room temperature, the barrier potential for a germanium PN junction is
a germanium is a flower
1 V
0.7V
0.3 V
39
Choose all the correct: Conductors have
5-8 valence electrons
1-3 valence electrons
high electrical resistance
low electrical resistance
40
The reverse bias limit is the
max reverse voltage that can be applied to a diode
max forward voltage that can be applied to a diode
41
A semi conductor is a tetravalent element
True
False
42
The lead connecting to the N type material is called
the anode
the K connection
the cathode
the P connection
43
Which is not a element used in semiconductors
Silicon
Germanium
Gold
44
Peak to Peak of an AC sine wave is
half the peak
twice the peak
always zero
E X I
45
The number of valence electrons determines if the material will act like an insulator or conductor
True
False
46
Aluminum is used as a heat sink because
it can be bent easily
it's nice and shiny
good heat transfer and resistance to corrosion
copper is actually used
47
The thermal joint compound
there is no such thing
increases the skunky smell
improves heat transfer
makes the connection permanent
48
When Ntype and P type material are formed side by side this creates
an AK junction
A NP junction
a KA junction
a PN junction
49
A photoconductive cell is known as
potato emit light if you apply enough voltage
a light emitting diode
light dependent resistor
a metal oxide varistor
50
An oscilloscope displays a graph of voltage over time.
False
True
51
The region where the P type and N type materials meet is called
the highway junction
the PN junction
the depletion region
the meeting point
52
The voltage across one resistor in a series resistive cct is a ratio to total resistance.
False
True
53
The period of a sine wave is
A general sequence of events that repeat
How many degrees in a sine wave
The frequency in hertz
the time it takes for one complete cycle
54
Which type of diode is used in fire alarm bells applications?
blocking
isolation
steering or directional
free wheeling
55
Adding an impurity to silicon is called
bonding
getting high
doping
stirring
56
Large current diodes are in the shape called
a hockey player
a hocky net
a hockey stick
a hockey puk
57
After an intrinsic material has been doped, it is an
Intrinsic material
Dirty material
extrinsic material
58
A Triavalent material is electrically neutral
True
False
59
Diodes are group into 3 current ratings
True
False
60
The formula for period is
T = f X 1
T = 1 X f
T = f / 1
T = 1 / f
61
The minimum amount of applied voltage to a diode to start conducting is called the barrier potential
False
True
62
An isolating diode could be used in a vehicle charging system
False
True
63
A free wheeling diode is used to control the destructive effect of cemf when a switch is opened in DC
False
True
64
A free wheeling diode is also known as
a diode that spins
a supression or protection diode
can be used effectively in AC or DC
an anti spiking diode
65
Extrinsic semi conductor material is either N type or P type
False
True
66
The lead connecting to the P type material is called
the P connection
the K connection
the anode
the cathode
67
Press fit diodes 150-500A are usually stud mounted with a pigtail
True
False
68
Choose the three common diode applications are
running diodes
free wheeling diodes
rectifier diodes
directional diodes
69
Choose all the correct: semiconductors
are neither good conductors or insulators
1-3 valence electrons
have 4 valence electrons
5-8 valence electrons
70
A volt meter is connected in parallel and a ammeter in series with a load
True
False
71
Medium current diodes are usually stud mounted or press fit
True
False
72
Heat sinks are most effective when mounted vertically because
the vertical effect
the heat sink effect
the chimney effect
the fan effect
73
The average value of DC in a constant DC source is the same as the maximum
True
False
74
Once breakdown voltage has been exceeded,
The diode needs to cool down
the diode operates normally
an avalanche in the Rocky mountains happens
avalanche current is seen
75
What does a Metal Oxide Varistor do?
surge suppression
ensures there is no oxidization
Filters heavy metals
Varies the metal and oxidizes
76
The effective value is also referred to as the root means square value
True
False
77
An AC meter displays
the dc average voltage
The peak AC
the rms value
78
The voltdrop across an axial type diode while in forward bias is
0.7V
120V
1.0V
0.3V
79
You must Isolate the circuit or the scope from ground to avoid a short circuit
True
False
80
The simplest practical PN junction is
a filter
a diode
a switch
a capacitor
81
A low current diode is usually 3 amps or less
True
False
82
A cycle is
Frequency
The time of one wave
A way to move: like bicycle or tricycle
A sequence of events that repeat
83
In ac coupled mode on an oscilloscope what is displayed
AC and DC
DC only
AC only
there is no such thing
84
The forward volt drop across larger diodes can be 1.2V- 1.8V
False
True
85
Pentavalent material is electrically neutral
True
False
86
The formula for any instantaneous voltage is
e= Emax X sine of theta
e= Emax X sine 0
e= Emax / Sine of theta
e= Emax X sine of 45
87
Breakdown voltage is not the same thing as avalanche voltage
False
True
88
Frequency is measured in
Cycles
Seconds
Hertz
F's
89
Pentavalent materials have how many valence electrons?
6
3
5
4
90
What is the typical forward operating voltages of LED's?
0.3V - 1.2V
1V- 2V
1.8 V- 2.2 V
1.8A - 2.2A
