*Fundamentals of Electricity & Electronics - 10% Flashcards
1
Q
What is capacitance measured in?
A
Farads
2
Q
A series circuit has a 12V power source and two resistors of 1-Ohm and 2-Ohms respectively. How many amps will flow when the circuit is closed?
A
3
Q
Opposition to the flow of electrons in ohms
A
Resistance
4
Q
The ability of two conductors separated by an insulator to hold an electrical charge
A
Capacitance
5
Q
The field generated around an electrical conductor
A
Induction
6
Q
A current that continuously reverses directions
A
alternating current
7
Q
A two-terminal device which can maintain a fixed voltage - such as a battery or wall outlet.
A
Voltage Source
8
Q
Anything which consumes electrical energy, such as lights, transformers, heaters and electric motors.
A
Load
9
Q
“Pressure” that causes electrons to flow and can be compared to water pressure which causes water to flow in a pipe.
A
Voltage
10
Q
The flow of an electric charge through a conductor - can be compared to the flow of water in a pipe
A
Current
11
Q
A device which converts mechanical energy into electrical energy.
A
Generator
12
Q
Positive terminal
A
Anode
13
Q
Negative terminal
A
Cathode
14
Q
The rate of doing work. Electric power is measured in watts or Volt-Amperes
A
Power (P)
15
Q
The units of measurement used in expressing power delivered to or consumed by an electrical device.
A
Watts (W)
16
Q
The law that states the relationship between Power, Voltage and current
A
Watts law
17
Q
What converts AC to DC? (Made with?)
A
Rectifier (Diodes in square)
18
Q
Explain basic construction of a transformer
A
Windings, core
19
Q
What voltage do Ni-Cad (NiCd) batteries have at full charge?
A
1.2V
20
Q
What is a transducer?
A
A device that converts one energy into another (ex: pressure to electrical or ultrasonic to electrical)
21
Q
What are examples of inductive transducers?
A
Touch pads, proximity sensors
22
Q
What is leakage current?
A
Current leaking to any unintended path or to ground (Any unused current)
23
Q
What is difference between transducer and electrode?
A
Transducer turns misc energies to misc output formats; Electrodes turn conduction into electrical signal
24
Q
Basic parts of transistor?
A
Base (what gets On/Off voltage), Collector (collects feedbackaround voltage), Emitter (Pushes voltage out from)
25
What do transistors act as?
Switch or amplifier
26
Symbol in diode for Anode/Cathode? (line/triangle)
Anode-triangle
Cathode-line
27
The IEEE standard for Ethernet communication:
A. 802.11
B. 802.3
C. 803.11
D. 811.3
B. 802.3
28
In a capacitive circuit:
A. Voltage leads current by 180 degrees
B. Current leads voltage by 90 degrees
C. Voltage leads current by 90 degrees
D. Current leads voltage by 180 degrees
B. Current leads voltage by 90 degrees
ELI the ICE man
Voltage/current always leads by 90 degrees
29
A few capacitors are in parallel. Calculate the total capacitance. The capacitor values are1uF, 2uF, 3uF, and 4uF. The total capacitance is:
A. 10 uF
B. 5 uF
C. 1 uF
D. 01 uF
A. 10 uF
Use same method as resistors in series
1µF + 2µF + 3µF + 4µF = 10µF
30
Solve this binary equation. Answer in a decimal number form. 11011+1111=
A. 42
B. 54
C. 15
D. 101010
A. 42
31
An Oscilloscope reads 10 volts peak to peak. What is the RMS voltage?
A. 707 VRMS
B. 7.07 VRMS
C. 3.54 VRMS
D. 1.414 VRMS
C. 3.54 VRMS
Peak Voltage X .707 = RMS voltage
5V X .707 = 3.54 VRMS
32
A heating element in an infant incubator uses 90 Watts of power and has a resistance of 1kΩ. Calculate the current through the heating element.
A. 0.09 milliamps
B. 0.300 milliamps
C. 300 milliamps
D. 9 milliamps
C. 300 milliamps
Power = I² X R B.
90W = I² X 1KΩ (90/1000) = I²
.09 = I²
.3 = I
33
A Triac is used to switch:
A. DC power
B. AC power
C. AC or DC power
D. FET gate current
B. AC power
the TRIAC a very convenient switch for AC circuits
34
Waveforms on an EEG Monitor are temporarily stored in:
A. ROM
B. RAM
C. EPROM
D. EEPROM
B. RAM
35
A GFCI normally has a trip point of
A. 2 mA
B. 3 mA
C. 4 mA
D. 6 mA
D. 6 mA
NFPA 99
36
A Nicad battery normally has:
A. 1.3 V per cell
B. 1.2 V per cell
C. 1.5 V per cell
D. 1.0 V per cell
B. 1.2 V per cell
Nickel-cadmium cells have a nominal cell potential of 1.2 volts (V).
37
A transformer has 1968 primary windings and 492 secondary windings (4:1) and the inputcurrent is 1 amp. Output current is?
A. 250 mA
B. 4 A
C. 500 mA
D. 2 A
B. 4 A
(Np/N/s) = (Ep/Es) = (Ip/Is)
(4/1) = (1/x) cross multiply 4=x
38
What would the inputs have to be on a 3 input OR gate to get a low out?
A. All low
B. All high
C. 2 lows 1 high
D. 2 high 1 low
A. ALL LOW
39
If a 4AH battery were replaced with a 2 AH with the same voltage rating, what would the result be?
A. Shorter run time.
B. Longer run time
C. Same run time
D. It would overheat the charging circuit
A. Shorter run time.
40
Which of the following is the unit of measure for capacitance?
A. Henrys
B. Farads
C. Working volts
D. Coulombs
B. FARADS
41
Which of the following is the protocol that provides communication across interconnected networks?
A. CSMA/CD
B. SMTP
C. TCP/IP
D. Routing table
C. TCP/IP
42
Which of the following is defined as volatile memory?
A. ROM
B. Flash
C. Stable
D. RAM
D. RAM
a. ROM non-volatile memory include read-only memory
b. Flash Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed.
c. Stable
d. RAM The most widely used form of primary storage today is a volatile form of random access memory (RAM), meaning that when the computer is shut down, anything contained in RAM is lost.
43
Which of the following is best determined by using an oscilloscope?
A. The relationship between AC and DC in a circuit.
B. The amount of AC current in a circuit.
C. The amplitude of a DC signal.
D. The voltage dropped across a resistor.
A. The relationship between AC and DC in a circuit.
44
Which of the following is the objective of a band-pass filter?
A. Allow a range of frequencies between an upper and lower cutoff
point to pass through.
B. Allow a range of frequencies below a upper cutoff frequency to
pass through.
C. Allow a range of frequencies above a lower cutoff frequency to
pass through.
D. Allow a range of frequencies above an upper cutoff frequency and
below a lower cutoff frequency to pass through.
A. Allow a range of frequencies between an upper and lower cutoff point to pass through.
45
Which of the following is the equivalent resistance of two 20 Ohm resistors in parallel in series with a 10 Ohm resistor?
A. 30 Ohms
B. 15 Ohms
C. 50 Ohms
D. 20 Ohm
D. 20 OHMS
Parallel: 1/((1/20)+(1/20)) = 10 Ohms
Add 10 Ohms from above with the 10 Ohm series resistor answer is 20 Ohms
46
In order for a basic power supply to operate correctly, which of the following is true?
A. The transformer must follow the regulator.
B. The rectifier must follow the filter.
C. The rectifier must follow the transformer.
D. The regulator must be before the filter.
C. The rectifier must follow the transformer.
47
10 to the minus 6 power is the prefix for which of the following?
A. Milli
B. Mega
C. Micro
D. Pico
C. Micro
48
Which of the following occurs when batteries are connected in series?
A. The current capability increases.
B. The voltage provided will increase.
C. The smaller battery will explode.
D. The voltage provided will decrease.
B. The voltage provided will increase.
Connecting batteries in series increases voltage
49
Current leads voltage in an ________ circuit by 90 degrees of phase.
capacitive
50
Capacitors oppose a change of ________
Voltage
51
Voltage drop across a resistor in a series circuit correlates ________ with its resistance.
directly
52
Decimal system is base ________.
10
53
Two of the same inductors in series ________ the overall inductance.
doubles
54
A unit of measurement for electrical current.
Full wave
55
Binary system is base ________.
2
56
The prefix "milli" means what?
one thousandth
57
Major advantages of linear power supply.
Simplicity, low noise, and good transient response.
58
The input of a logical NOT gate is "LOW" or logic level "0". What is the output?
"HIGH" or logic level "1"
59
The resistance of a typical medical thermistor decreases as temperature ________.
increases
60
Two identical resistors in parallel ________ the overall resistance.
halves
61
120 VAC line voltage is an RMS value. Is the actual peak voltage higher or lower?
Higher
62
What is frequency of 120 VAC line voltage in the US?
60 Hertz
63
Electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one of which includes the unknown resistance. Can be used to very accurately measure resistance.
Wheatstone bridge
64
Voltage leads current in an ________ circuit by 90 degrees of phase.
inductive
65
The inputs of a three-input logical OR gate are all "HIGH" or logic level "1". What is the output?
"HIGH" or logic level "1"
66
A computer power supply is typically a linear or switched-mode power supply?
Switched mode
67
Two identical batteries in parallel doubles the available current or voltage?
current
68
A unit of measurement for electrical capacitance.
Farad
69
An AC power cord with blue, brown, and green has the hot on ________ and neutral on ________.
brown, blue
70
The prefix "mega" means what?
denotes multiplication by one million
71
The prefix "tera" means what?
denotes multiplication by one trillion
72
2 (decimal) in base 2 is ________
10
73
The product of current (Amperes) and resistance (Ohms).
voltage (Volts)
74
A unit of measurement for electrical power.
Watt
75
Classification of transistor amplifier circuit in which the input is applied across the emitter and base and output is taken from across the collector and base. Here, the collector is "common" to the input and output.
common collector
76
Octal system is base ________
8
77
120 VAC line voltage is an RMS value. What is the actual (nominal) peak to peak voltage?
340 Vpp
78
A power supply characterized by the use of a relatively large transformer, bridge rectifier, filter capacitors, and voltage regulator.
Linear
79
The inputs of a two-input logical XOR gate are all "HIGH" or logic level "1". What is the output?
"LOW" or logic level "0"
80
The prefix "giga" means what?
denotes multiplication by one billion
81
The prefix "micro" means what?
one millionth
82
What 3-lead electrical component allows a small voltage or current to switch on/off a much larger electrical voltage or current?
transistor
83
The product of current (Amperes) and voltage (Volts).
power (Watts)
84
Formula for time constant in RC circuit. RC time constant = ?
R X C
85
Major advantages of a switched mode power supply.
Much higher power to weight ratio and much higher efficiency
86
Resistance is ________ in a series circuit.
additive
87
ELI the ICE man is an acronym for remembering current and voltage phase difference in a circuit that is predominantly
reactive (capacitive or inductive)
88
Forward biasing a typical PN junction in a silicon diode will cause a voltage drop of ________ Volts.
0.7
89
The prefix "pico" means what?
transistors
90
What 2-lead electrical component allows current in one direction, but not the other
diode
91
A forward biased diode will allow current to flow, true or false?
True
92
A unit of measurement for electrical potential.
Volt
93
In an electrical circuit, a bleeder resistor ________ a circuit.
discharges
94
What piece of electronics test equipment can display an AC waveform superimposed on a DC level?
Oscilloscope
95
Formula relating frequency and time period.
f=1/t
96
11111111 (binary) in decimal is ________.
255
97
A form of opposition generated by components in an electric circuit when alternating current (AC) passes through it.
Reactance
98
10 (decimal) in binary is ________.
1010
99
Two of the same capacitors in parallel ________ the overall capacitance.
doubles
100
A load is purely resistive when the combination of inductive reactance and capacitive reactance is ________.
zero
101
A reversed biased diode will block current flow, true or false?
True
102
Inductors oppose a change of ________.
Current
103
The inputs of a three-input logical AND gate are all "HIGH" or logic level "1". What is the output?
"HIGH" or logic level "1"
104
A single diode can produce what type of rectification of AC?
Half wave
105
A unit of measurement for electrical induction.
Henry
106
Classification of transistor amplifier circuit in which the input is applied across the emitter and base and output is taken from across the collector and base. Here, the base is "common" to the input and output.
common base.
107
The inputs of a three-input logical NAND gate are all "HIGH" or logic level "1". What is the output?
"LOW" or logic level "0"
108
The prefix "kilo" means what?
denotes multiplication by one thousand
109
A device with a P-type material adjoined to an N-type material is a ________.
diode
110
Capacitance is ________ in a parallel circuit.
additive
111
2πfL, where f is frequency and L is inductance, is the formula for what?
Inductive reactance
112
The inputs of a two-input logical XNOR gate are all "HIGH" or logic level "1" or all low logic level "0". What is the output?
"HIGH" or logic level "1"
113
Current is the same in all nodes of a ________ circuit.
series
114
120 VAC line voltage is an RMS value. What is the actual (nominal) peak voltage?
170 Vp
115
Classification of transistor amplifier circuit in which the input is applied across the base and collector and output is taken from across the collector and emitter Here, the emitter is "common" to the input and output.
common emitter
116
AC voltage is often expressed as RMS. RMS stands for what?
Root mean square
117
1/(2πfC), where f is frequency and C is capacitance, is the formula for what?
Capacitive reactance
118
Hexadecimal system is base ________.
16
