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ELECTRONICS COMPILATION

1. What is the bandgap energy for diamonds?

a. 2.5eV b.1.1eV

c.5.6eV d. 0.1eV

2. _______________ allows simplifying a one-port circuit to a current source in parallel with an impedance.

a. Norton’s Theorem b. Thevenin’s Therorem c. Kirchoff’s Current Law

d. Faraday’s Law of Magnetic Induction

3. Charge carriers move in semiconductors via two mechanisms: _____ and _______.

a. drift and diffusion b. drift and avalanche c. avalanche and diffusion d. none of the above

4. The diffusion current density is proportional to the _________ of the carrier concentration

a. gradient b. curl

c. divergence d. laplacian

5. The ___________ is the minimum energy required to dislodge an electron from its covalent

bond.

a.barrier potential b. bandgap energy c. potential energy d. diffusion energy

6. Under a high reverse bias voltage, pn pn junctions break down, conducting a very high current. Depending on the structure and doping levels of the device, ____________ breakdown may occur.

a. Zener b. Avalanche

c. Drift d. answers a or b

7. The statement” A voltage-dependent current source can form an amplifier along with a load resistor” is

a. True b. False

c. Cannot be determined d. Sometimes True 8. For proper operation, the____________________ is forward-biased and the _____________________ is reverse-biased.

a. base-emitter junction, collector-emitter junction b. base-emitter junction, base-collector junction c. collector-base junction, base-emitter junction d. collector-emitter junction, collector-base junction 9. The ________________ of the bipolar transistor consists of an exponential voltage-dependent

current source tied between the collector and emitter, and a diode (accounting for the base

current) tied between the base and emitter. a. r-paramter model

b. h-parameter model c. small signal-model d. large-signal model

10. The ______ stage provides a moderate voltage gain, a moderate input impedance, and a moderate

output impedance. a. common-drain b. common-collector c. common-base d. common-emmiter

11. The ___________ provides a voltage gain less than unity, a high input impedance, and a low output impedance, serving as a good voltage buffer

a. emitter follower b. common base c. common emitter d. common source

12. MOSFETs operate in the ________ region if the drain voltage is more than one threshold below the gate voltage

a. triode b. diode

c. negative resistance d. constant current

13. A measure of the small-signal performance of voltage-dependent current sources is the _____________ defined as the change in the output current divided by the change in the input voltage.

a. impedance b. conductance c. transconductance d. reluctance

14. The impedance seen looking into the gate of a MOSFET is equal to ________

a. infinity b. r0

c. 1 / gm d. zero

15. The _______________ topology exhibits a nominal gain equal to one plus the ratio of

two resistors. The circuit also suffers from a gain error that is inversely proportional to the

gain of the op amp. a. noninverting amplifier b. inverting amplifier c. summing amplifier d. voltage follower

16. Placing a bipolar device around an op amp provides a _____________function

a. linear b. parabolic c. exponential d. logarithmic

17. Op amps suffer from various imperfections, including dc offsets and input bias currents.

These effects impact the performance of various circuits, most notably,____________.

a. zero-level detector b. summing amplifier c. differentiators d. integrators

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18. Stacking a transistor atop another forms a _______ structure, resulting in a high output

impedance. a. darlington b. stack c. cascade d. cascode

19. Bipolar differential pairs exhibit a

____________input/output characteristic. The tail current can be mostly steered to one side with a differential input of about 4Vt.

a. parabolic b. logarithmic

c. hyperbolic tangent d. exponential

20. As the frequency of operation increases, capacitances exhibit a ______________, reducing

the gain. The gain thus rolls off at high signal frequencies. a. same impedance

b. slightly higher impedance c. lower impedance

d. significantly higher

21. To obtain the frequency response, we must derive the ___________ of the circuit.

a. logarithmic behavior b. roll-off rate

c. gain

d. transfer function

22. A capacitance tied between the input and output of an inverting amplifier appears at the input

with a factor equal to one minus the gain of the amplifier. This is called _______________.

a. Capacitance-gain effect b. Miller effect

c. Thevenin effect d. Faraday effect

23. The ________of a feedback system can, in principle, be obtained by breaking the loop,

injecting a test signal, and calculating the gain as the signal goes around the loop. It determines many properties of feedback systems, e.g., gain, frequency response, and I/O impedances.

a. loop gain b. transfer function c. negative feedback d. signal flow

24. To avoid oscillation, the gain crossover frequency must __________the phase crossover frequency.

a. fall below b. rise above c. be equal d. a factor of

25. The crossover distortion resulting from the dead zone can be reduced by biasing the push-pull

transistors for a small quiescent current a. True

b. False

26. In low-distortion applications, the output stage may be embedded in a _________

to suppress the nonlinearity. a. open loop

b. positive feedback loop c.negative feedback loop d. none of the above

27. A push-pull stage operating at high temperatures may suffer from _____________, whereby

the elevated temperatures allow the output transistors to draw higher currents, which in turn

makes them dissipate even more. a. avalanche effect

b. diffusion effect c. thermal runaway d. thermal breakover

28. The ___________ response provides a sharper transition than Butterworth at the cost of some

ripple in the passband and stopbands. It contains n complex poles on an ellipse

a. Thomas b. Buttord c. Elliptic d. Chebyshev

29. A phenomenon that occurs for large reverse voltages across a pn junction where the free electrons are

accelerated to such high speeds that they can dislodge valence electrons.

a. Piezoelectric effect b. Zener Effect c. Recombination d. Avalanche effect

30. A graph showing the gain or phase performance of an electronic circuit at various frequencies.

a. Ogive graph b. Bode plot

c. Gain-frequency curve d. Performance graph

31. What do you call the ohmic resistance of the semiconductor?

a. Dynamic resistance b. Static resistance c. Bulk resistance

d. Semiconductor resistance

32. The metaphor used to describe the action of an SCR when it is used to protect a load against supply.

a. Surge b. Limiter c. Breaker d. Crowbar

33. A value that tells you how much to reduce the power rating for each degree above the reference temperature given on the data sheet.

a. Reduction factor b. Derating factor

c. Temperature coefficient d. Attenuation

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34. It is the process of adding impurity element to an intrinsic semiconductor to change its conductivity.

a. Impurification b. Crystallization c. Recombination d. Doping

35. A condition where the transistor is operating at the upper end of the load line with a base current that is one-tenth of the collector current.

a. Full saturation b. Hard saturation c. Mid saturation d. Avalanche

36. The pattern appearing on an oscilloscope when harmonically related signals are applied to the horizontal and vertical inputs.

a. Lissajous’ pattern b. Shockley’s pattern c. Braun’s pattern d. Lee de Forest’s pattern

37. A connection of two transistors connected with positive feedback to simulate the action of a thyristor.

a. Complementary b. Latch

c. Push pull d. Switch

38. It refers to the average amount of time between the creation and recombination of a free electron and a hole.

a. Recombination time b. Delay time

c. Conduction time d. Life time

39. A filter that blocks a signal with at most one frequency. a. Brick wall filter

b. Cauer filter c. Notch filter d. Butterworth filter

40. A term use to describe the death of amplification. a. Oscillation

b. Attenuation c. Degradation d. Hysteresis

41. The voltage that provides the border between the ohmic region and the constant current region of a depletion-mode device when the gate to source voltage is zero.

a. Threshold voltage b. Peak point voltage c. Valley point voltage d. Pinch off voltage

42. A basic circuit that a designer can modify to get more advanced circuits.

a. Model circuit b. Miniature circuit c. Prototype d. Hybrid

43. It is a comparator with hysteresis. a. Schmitt trigger

b. Hysteresis circuit c. Trigger-comparator

44. Which of the following special purpose diode doesn’t have depletion layer?

a. Tunnel diode b. Schottky diode c. Varactor diode d. Zener diode

45. It is define as a large initial current that flows through the diode of a rectifier.

a. Bleeder current b. Surge current c. Transient current d. Saturated current

46. It is defined as a four-layer semiconductor device that acts as a latch.

a. Thyrector b. Transistor c. Transformer d. Thyristor

47. It is the value of the input voltage that switches the output of a comparator.

a. Trigger b. Trip point c. Latch d. Knee

48. It is a device that acts like two back-to-back-zener diodes.

a. Varistor b. Varactor

c. Complementary zener d. Zener latch

49. What do you call a thin slice of crystal used as a chassis for integrated components.

a. Substrate b. Base c. Wafer d. Impurity

50. What is the other term for zener effect? a. Avalanche effect

b. Piezoelectric effect c. High field emission d. Breakdown effect

51. Calculate the efficiency of a transformer-coupled class A amplifier for a supply of 12 V and outputs of 6V. a.50% b. 25% c. 12.5% d. 10%

( )

( ) Resulting in

(4)

52. For a class B amplifier providing a 20-V peak to a 16-Ω load (speaker) and a power supply of Vcc = 30 V, determine the circuit efficiency.

a.45.2% b. 66.67% c. 78.5% d. 52.3%

( ) ( ) ( )

( )

( ) ( )( )

( ) ( ) ( ) For resulting efficiency of

( )(

53. For a class B amplifier using a supply of Vcc = 30 V and driving a load of 16Ω, determine the maximum output power.

a.28.13W b. 35.81W c. 41.23W d. 54.91W Maximum ( ) ( ) ( )

54. For a class B amplifier using a supply of Vcc = 30 V and driving a load of 16Ω, determine the transistor dissipation a.3.7W b. 4.7W c. 5.7W d. 6.7W

Maximum ( ) * ( )

+

55. Calculate the efficiency of a class B amplifier for a supply of Vcc = 24 V with peak output voltages of VL (p) =

22 V. a.62% b. 68% c. 72% d. 78% ( ) ( ) 56. Calculate the total harmonic distortion for the

following amplitude components: fundamental amplitude of 2.5 V, second harmonic amplitude of 0.25 V, third harmonic amplitude of 0.1 V, and fourth harmonic amplitude of 0.05 V. a.11% b. 12% c. 13% d. 14% | | || | | || | | || √ √( ) ( ) ( )

57. Determine what maximum dissipation will be allowed for an 80-W silicon transistor (rated at ) if the reading is required above by a derating factor of 0.5W/ at case temperature of .

a.25W b. 30W c. 35W d. 40W

( ) ( ) ( )( ) ( ) 58. A silicon power transistor is operated with a heat sink ( ) the transistor, rated at150 W

( ) , and the mounting insulation has . What maximum power can be dissipated if

the ambient temperature is a.61.5W b. 71.5W c. 81.5W d. 91.5W

59. A dc voltage supply provides 50 V when the output is unloaded. When connected to a load, the output drops to 56 V. Calculate the value of voltage regulation. a.4.1% b. 7.1% c. 5.7% d. 10.7%

60. Calculate the ripple voltage of a full-wave rectifier with a 100-μF filter capacitor connected to a load drawing to a load drawing 50 mA

a.1.2V b. 2.5V c. 2.7V d. 3.1V ( ) ( )

61. Calculate the filter dc Voltage of a full-wave rectifier with a 100-μF filter capacitor connected to a load drawing to a load drawing 50 mA if the peak rectifier voltage is 30 V. a.25.4V b. 26.1V c. 27.9V d. 28.6V ( ) 62. Calculate the ripple of a capacitor filter for a peak rectified voltage of 30 V, capacitor C= 100μF, and a load current of 50 mA. a.3.7% b. 4.3% c. 5.1% d. 6.9% ( ) ( ) 63. Calculate the input bias currents at the non-inverting and inverting terminal respectively of an op=amp having specified values of IIO = 5nA and IIB = 30 nA.

a.Both 32.5nA b. Both 27.5nA c. 27.5nA; 32.5nA d. 32.5nA; 27.5nA

64. Determine the cutoff frequency of an op-amp having specified values B1 = 1 MHz and AVD = 200 V/mV.

a.4Hz b. 5Hz c. 1kHz d. 1MHz

65. For an op-amp having a slew rate of SR = 2V/µs, what is the maximum closed loop voltage gain that can be used when the input signal varies by 0.5 V in 10 µs? a.10 b. 20 c. 30 d. 40

66. Determine the output voltage of an op-amp for input voltages of Vi1 = 150 µV and Vi2 = 140 µV. The amplifier has

a differential gain of Ad =4000 and the value of CMRR is

100.

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67. If an amplifier with gain of -1000 and feedback of β=-0.1 has a gain change of 20% due to temperature; calculate the change in gain of the feedback amplifier a.10% b. 0.2% c. 20% d. 1%

| | | | | | | ( )|(20%) = 0.2%

68. A transistor has a collector current of 10mA and a base current of 40uA. What is the current gain of the transistor a.20 b. 30 c. 40 d. 50

β=10mA/40uA=50

69. A 2N3904 has VCE=10V and IC=20mA. What is the power dissipation?

a.0W b. 100mW c. 200mW d. 2N3904 is limited to 10mW

PD=10V(20mA)=200mW

70. A zener regulator has an input voltage that may vary from 22 to 30V. If the regulated output voltage is 12V and the load resistance varies from 140Ω to 10kΩ, what is the maximum allowable series resistance?

a.140Ω b. 76.4 Ω c. 280 Ω d. 117 Ω (

) 71. It is sometimes called hot-carrier diode.

a. Shockley diode b. Schottky diode c. Gunn Diode d. Tunnel diode

72. A zener regulator has an input voltage ranging from 15 to 20V and a load current ranging from 5 to 20mA. If the zener voltage is 6.8V, what is the maximum allowable series resistance?

a.750Ω b. 410 Ω c. 1000Ω d. 2000 Ω (

)

73. A 2N5668 has VGS(off)=-4V and IDSS=5mA. What are the gate voltage and drain current at the half cutoff point?

a.-1V; 1mA b. -2V; 1.25mA c. -4V; 5mA d. 0; 0 74. A network that employ diodes to remove away a portion of an input signal without distorting the remaining part of the applied waveform

a. Clamper b. Rectifier c. Regulator d. Clipper

75. Atom with four valence electrons is called ____. a. Trivalent

b. Tetravalent c. Quadvalent d. Pentavalent

76. The term applied to any semiconductor material that has been carefully refined to reduce the number of impurities to a very low-essentially as pure as can be made available through modern technology.

a. Intrinsic b. Crystal c. Lattice d. Solid

77. Who discovered electrons in 1897? a. J. Thompson

b. E. Rutherford c. J. Chadwick d. J. Maxwell

78. What is the typical energy gap of silicon semiconductor?

a.0.03eV b. 0.67eV c. 1.1eV d. 1.43eV 79. Which of the following semiconductor material is sensitive to temperature change?

a. Carbon b. Germanium c. Silicon d. GaAs

80. It occurs when a conduction-band electron loses energy and falls back into a hole in the valence band.

a. Ionization b. Doping c. Electron-hole d. Recombination

81. Which of the following is not a pentavalent atom? a. Phosphorus

b. Antimony c. Arsenic d. Boron

82. How does minority carriers produced? a. Doping

b. Ionization

c. Thermally produced d. Light energy

83. It is an extremely small amount of current that exists in a reverse biased diode.

a. Forward saturated current b. Reversed saturated current c. Forward leakage current d. Zener current

84. What is the typical reverse saturated current of a silicon diode?

a.1uA b. 10uA c. 10pA d. 1pA

85. What is the typical range of reverse breakdown voltage of silicon diode?

a. 2-200V b. 50-1kV c. 50-400V d. 100-10kV

86. The time required for the minority carriers to return to the majority carrier state in the opposite material.

a. Transition time b. Time constant c. Rise time d. Storage time

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87. Determine the thermal voltage of a diode at 27°C (common temperatures for components in an enclosed operating system)

a.20mV b. 26mV c. 30mV d. 1V Vt =kT/q=(1.38x10-23J/K)(273+17)/1.6x10-19C

= 26mV

88. What is the knee voltage of a silicon diode at 75°C? a.0.7V b. 2.1V c. 0.58V d. 0V

(75-25)°C*2.5mV/°C = 0.125V New Vknee = 0.7-0.125 = 0.575V

89. At 20°C, the reverse saturation current of a silicon diode is 10nA, what is its value when the temperature increases to 100°C?

a.0.32uA b. 50nA c. 10nA d. 0A 100 °C / 20°C = 5

New Ireverse = 25(10nA)= 0.32uA

90. A silicon diode is in series with 1kΩ resistor and a forward biasing voltage supply of 10V. If r’d is 10Ω, what is

the anode to cathode current and voltage? a. 9.3mA, 0.7V b. 9.3mA,0.79V c. 9.21mA,0.7V d. 9.21mA,0.79V IF=(10-0.7)/(10+1k)=9.21mA VF=0.7+10(9.21mA=0.79V

91. What is the wavelength of the light produced by an LED with an energy gap level of 1.43 eV?

a. 569nm b. 669nm c. 768nm d. 869nm

λ=hc/Eg =(6.626x10-34Js*3x108m/s) /(1.43eV*1.6x10-19J/eV)

= 869nm

92. What does FPGA stands for? a. Field p-type gate array

b. Field programmable gate arrangement c. Field programmable gate array

d. FET programmable gate array 93. Find the 2’s complement of 10110010.

a. 01001101 b. 01001100 c. 11001101 d. 10111101

94. Convert the binary number 11000110 to gray code a. 1011101

b. 10100111 c. 10000101 d. 10100101

95. Which of the following can be used as universal gate? a. AND

b. OR c. NAND d. NOT

96. A logic gate that produces a HIGH output only when its two inputs are at opposite levels.

a. OR b. XOR c. NOR d. XNOR

97. The complement of a sum of variables is equal to the product of the complements

of the variables.

a. Boolean’s Rule

b. De Morgan’s Theorems c. Baudot’s Law

d. Karnaugh’s Rule

98. Which of the following expression is in standard SOP form?

a. F=ABC+AB’C+A’B’C’ b. F=A’+BC+ABC’ c. F=AB+AC+BC d. All of the above

99. In a 4 variable K-map, what is the binary value for the cell in the lower right corner?

a. 0000 b. 1111 c. 0101 d. 1010

100. It is a digital circuit that adds two bits and an input carry to produce a sum and an output carry.

a. Half adder b. Full adder c. Demultiplexer d. Encoder

101. Which of the following is the invalid state for RS flip flop?

a. S=0; R=0 b. S=0; R=1 c. S=1; R=0 d. S=1; R=1 102. In T flip flop, T stands for:

a. Time b. Trip c. Transient d. Toggle

103. How many flip-flop/s is/are need to produce 2kHz frequency from 8kHz input?

a.1 b. 2 c.3 d. 4

104. A flip-flop is in the toggle condition when: a. J=0; K=0

b. J=0; K=1 c. J=1; K=0 d. J=1; K=1

105. How many flip-flops are needed to produce 4-bit asynchronous counter?

a.2 b. 4 c. 6 d. 8

106. How many flip-flops are needed to produce modulus-12 asynchronous counter?

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107. What do you call the number of unique states through which a counter will

sequence? a. State b. Sequence c. Modulus d. Counts

108. Asynchronous counters are known as: a. ripple counters

b. multiple clock counters c. decade counters d. modulus counters 109. The modulus of a counter is

(a) the number of flip-flops

(b) the actual number of states in its sequence (c) the number of times it recycles in a second (d) the maximum possible number of states 110. Three cascaded modulus-10 counters have an overall modulus of

a.30 b. 100 c. 1000 d. 10000

111. The terminal count of a modulus-13 binary counter is a. 0000

b. 1111 c. 1101 d. 1100

112. The difference between the two op-amp input currents is called ______.

a. Input Offset Current b. Input Bias Current c. Op-Amp Input Current d. Differential Mode Current

113. A circuit whose output voltage is proportional to the area under the curve of the input voltage.

a. Differentiator b. Comparator c. Integrator

d. Summing Amplifier

114. A circuit whose output voltage is proportional to the slope of the input voltage.

a. Differentiator b. Comparator c. Integrator

d. Summing Amplifier

115. A filter response that exhibits an equiripple amplitude response in the pass band.

a. Notch Filter response b. Chebyshev Response c. Bessel Response d. Butterworth Response

116. A filter response that exhibits maximum flatness possible in the pass band.

a. Notch Filter response b. Chebyshev Response c. Bessel Response d. Butterworth Response

117. The ____ gate is called the “all or nothing” gate. a.) AND

b.) OR c.) NOR d.) XOR

118. Express the Boolean function F= xy + x’z in a product of maxterm form.

a. F = (x’+y)(x+y)(y+z) b. F = (x’+y)(x+z)(x+y) c. F = (x+y’)(x+z)(y+z) d. F = (x’+y)(x+z)(y+z)

119. In switching transistors, what do you call the time between the changing state of the input and the beginning of a response in the output?

a. Delay time b. Rise time c. Fall time d. Storage time

120. The current gain of a common-base BJT configuration is _____________.

a. just less than 1 b. negligibly small c. very high

d. just greater than 1

121. It is desired to design a phase-shift oscillator using an FET having gm= 5000 , rd= 40 and a feedback circuit

whose resistance value R= 10 . Select the value of the capacitor appropriate for oscillator operation of 1 kHz. a. 6.5nF b. 1.62nF c. 8.12nF √ √ ( )( )

122. The current gain of a Darlington pair is called ________.

a. superbeta b. beta c. alpha d. superalpha

123. The total dB gain of a three stage system is 120dB. Determine the dB gain of the third stage if the second stage is twice the dB gain of the first stage and the third is 2.7 times the dB gain of the first.

a. 57 dB b. 30 dB c. 21 dB d. 62 dB ( )

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124. A ______ is a dc–dc converter with an unregulated input dc voltage and a regulated output voltage. The converter circuitry consists of arrangements of inductor, capacitors, diodes, and transistors. The transistors are switched between the ON state (saturation) and the OFF state (cutoff) at rates that typically range from 10 kHz to 40 kHz.

a. switched-mode power supply b. regulated power supply c. unregulated power supply d. dc power supply

125. Logarithmic amplifiers, together with exponential amplifiers are used to perform analog multiplication. These can be constructed by using an operational amplifier and a diode. Where and how should the diode be placed so that the circuit will work as a logarithmic amplifier?

a. Forward biased in the feedback path, replacing Rf of

an inverting op-amp

b. Reversed biased in the feedback path, replacing Rf of

an inverting op-amp

c. Forward biased in the input, replacing Ri of an

inverting op-amp

d. Reversed biased in the input, replacing Ri of an

inverting op-amp

126. The time sequence of inputs, outputs and flip-flop states can be enumerated in a _______. This consists of four sections labeled the present state, input, output and next state.

a. state table b. truth table c. state diagram d. truth diagram

127. In digital design of combinational logic circuits, what do you call the term that refers to the connection of the output of one device to the input of a similar device allowing one device to drive the other in order to expand the operational capability?

a. Cascading b. Cascading c. Fanning

d. Cross-connecting

128. In computers, what do you call a relatively small, high-speed memory that stores the most recently used instructions or data from the larger but slower main memory?

a. cache memory b. register

c. random access memory d. flash memory

129. What is the ratio of the input impedance with series feedback to that without feedback?

a. 1 + BA b. BA c. B d. 1

130. Which of the following is required to start oscillation? a. BA > 1

b. The phase shift around the feedback network must be 180 degrees.

c. Both BA > 1 and the phase shift around the feedback network must be 180 degrees.

d. None of the above

131. Only the condition BA = _____ must be satisfied for self-sustained oscillations to result.

a. 0 ? b. -1 ? c. 1 ?

d. None of the above ?

132. In the IC phase-shift oscillator, what should the ratio of feedback resistor Rf to R1 be?

a. Zero

b. Greater than -29 c. Less than 29 d. Any value

Av = 1 + (Rf/Ri) = 1 + (1k/100) = 11

133. In the Wien bridge oscillator, which of the following is (are) frequency-determining components?

a. Both resistors b. Both capacitors

c. Both resistors and capacitors d. None of the above

134. What is the typical value of quality factor for crystal oscillators?

a. 20,000 b. 1,000 c. 100 d. 10

135. In which of the following applications is a pulsating dc voltage suitable?

a. Battery charger b. Radio

c. Stereo system d. Computer

136. Across which of the following components of a power supply does the average (dc) voltage exist?

a. Diodes

b. Secondary of transformer c. Capacitor filter

d. None of the above

137. What is the purpose of an additional RC filter section in a power supply circuit?

a. Increase the dc voltage component b. Increase the ac voltage component c. Decrease the ac voltage component d. None of the above

138. In a simple series regulator circuit, which of the following components is the controlling element?

a. Load resistor b. Zener diode c. Transistor

d. None of the above

139. What is the range of gm for JFETs? a. 1 uS to 10 uS

b. 100 uS to 1000 uS c. 1000 uS to 5000 uS d. 10000 uS to 100000 uS

140. For what value of ID is gm equal to 0.5 gm0?

a. 0 mA b. 0.25 IDSS c. 0.5 IDSS

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141. Which of the following transistor has depletion and enhancement types? a. BJT b. JFET c. MOSFET d. Diode

142. What is the level of IG in an FET?

a. Zero b. Equal to ID

c. Depends on VDS

d. Undefined

143. The region to the left of the pinch-off locus is referred to as the _____ region.

a. saturation b. cut-off

c. ohmic

d. None of the above

144. The drain current will always be one-fourth of IDSS as long as the gate-to-source voltage is _____ the pinch-off value.

a. one-fourth b. one-half c. three-fourths d. None of the above

145. How many terminals can a MOSFET have? a. 2

b. 3 c. 4 d. 3 or 4

146. It is the insulating layer of _____ in the MOSFET construction that accounts for the very desirable high input impedance of the device.

a. SiO b. GaAs c. SiO2 d. HCl

147. The transfer curve is not defined by Shockley's equation for the _____.

a. JFET b. DMOSFET c. EMOSFET

d. None of the above

148. Which of the following FETs has the lowest input impedance?

a. JFET b. DMOSFET c. EMOSFET

d. None of the above

149. How many orbiting electrons does the germanium atom have? a. 4 b. 14 c. 32 d. 11 150. One eV is equal to _____ J. a. 6.02 E23 b. 1.6 E–19 c. 6.25 E18 d. 1.66 E–24

151. What unit is used to represent the level of a diode forward current?

a. pA b. nA

c. A d. mA

152. Calculate the power dissipation of a diode having ID

= 40 mA.

a. 28 mW b. 28 W

c. 280 mW PD = VD x ID = 0.7V x 40 mA = 28 mW

153. Which capacitance dominates in the reverse-bias region?

a. Depletion b. Conversion

c. Diffusion d. None of the above

154. Which capacitance dominates in the forward-bias region?

a. Depletion b. Conversion

c. Diffusion d. None of the above

155. What does a high resistance reading in both forward- and reverse-bias directions indicate?

a. A good diode b. An open diode

c. A shorted diode d. A defective ohmmeter

156. Determine the nominal voltage for the Zener diode at a temperature of 120° C if the nominal voltage is 5.1 volts at 25° C and the temperature coefficient is 0.05%/° C. a. 4.6 V

b. 4.86 V c. 5.1 V d. 5.34 V

V120C = V25C + V25C (120C – 25C) ( .0005/C) = 5.34 V

157. What is the maximum power rating for LEDs? a. 150 mW

b. 500 mW c. 1 W d. 10 W

158. The _____ diode model is employed most frequently in the analysis of electronic systems.

a. ideal b. practical c. piecewise-linear d. None of the above

159. At what region of operation is the base-emitter junction forward biased and the base-collector junction reverse biased?

a. Saturation b. Linear or Active c. Cut-off

(10)

160. For the BJT to operate in the saturation region, the emitter junction must be _____-biased and the base-collector junction must be _____-biased.

a. forward, forward b. forward, reverse c. reverse, reverse d. reverse, forward

161. Which of the following voltages must have a negative level (value) in any NPN bias circuit?

a. VBE

b. VCE

c. VBC d. None of the above

162. Which of the following is referred to as the reverse transfer voltage ratio?

a. hi b. hr

c. hf d. ho

163. Which of the following techniques can be used in the sinusoidal ac analysis of transistor networks?

a. Small-signal b. Large-signal

c. Small- or Large-signal d. None of the above

164. The _____ model suffers from being limited to a particular set of operating conditions if it is to be considered accurate.

a. hybrid b. re c. Thevenin

d. None of the above

165. What is the unit of the parameter ho of a BJT? a. Volt

b. Siemen c. Ohm d. Unitless

166. What is the typical value of the current gain of a common-base configuration?

a. Less than 1 b. Between 1 and 50 c. Between `100 and 200 d. Undefined

167. What does the negative sign in the voltage gain of the common-emitter fixed-bias configuration indicate? a. The output and input voltages are 180º out of phase. b. Gain is smaller than 1.

c. Gain is larger than 1. d. None of the above

168. The _____ configuration is frequently used for impedance matching.

a. fixed bias

b. voltage-divider bias c. emitter-follower d. collector feedback

References

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