[ELECS] ELECTRONIC CIRCUITS
100. It is the current required by the inputs of the amplifier to properly operate the first stage A. Input bias current B. Slew rate C. Input offset current D. Output offset current
: A
107. Refer to the given figure. This circuit is known as O +Voc OOOOO 카3 C A. a Clapp oscillator. B. an Armstrong oscillator. C. a Colpitts oscillator. D. a Hartley oscillator.
: A
113. What is the output waveform? IDEAL OPAMP 2 3 + 1 Uı Vout y 1000 Hz I A. sine wave B. square wave C. +15 V D. -15 V
: A
119. What happens to the input resistance of an amplifier employing voltage series feedback? A. Increased B. Remains the same C. Decreased D. Equals infinity
: A
123. The voltage follower has a: A. closed-loop voltage gain of unity B. small open-loop voltage gain C. closed-loop bandwidth of zero D. large closed-loop output impedance
: A
128. Which of the push-pull amplifiers is presently the most popular form of the class B power amplifier? A. Quasi-complementary B. Transformer-coupled C. Complementary-symmetry D. None of the above
: A
130. What is the most common form of coupling? A. RC B. Resistor C. Impedance D. Transformer
: A
132. A mathematical operation that determines the rate of change of a curve is called A. differentiation B. integration C. curve averaging D. linear regression
: A
156. circuit that can change the frequency of oscillation with an application of a do voltage is sometimes called A. a voltage-controlled oscillator. B. a crystal oscillator. C. a Hartley oscillator. D. an astable multivibrator.
: A
165. An instrumentation amplifier has extremely high good and high A. input impedance, common-mode rejection, gain B. noise factor, grounding, power C. working voltages, current capacity, output impedance D. output gain, output loading, power
: A
173. Oscillator with best frequency stability is A. Crystal oscillator B. Phase shift oscillator C. Clapp oscillator D. Hartley oscillator
: A
180. It is the ability of the filter circuit to reduce the amplitude of the unwanted frequencies below the level of the desired output frequency. A. Attenuation B. Discrimination C. Elimination D. All of the above
: A
183. The major difference between ground and virtual ground is that virtual ground is only a: A. voltage reference B. current reference C. power reference D. difference reference
: A
189. Given a voltage reference of+IV, we can get an output voltage of -15V by using alan A. Inverting amplifier B. Non inverting amplifier C. Differential amplifier D. Instrumentation amplifier
: A
190. Assertion (A): A tuned amplifier uses a parallel tuned circuit Reason (R): A tuned amplifier is used to amplify a narrowband frequencies A. Both A and R are correct and Ris correct explanation for A B. Both A and R are correct but R is not correct explanation for A C. A is correct R is wrong D. A is wrong R is correct
: A
196. What is the ratio of the input impedance with series feedback to that without feedback? A. 1 + BA B. BA C. B D. 1
: A
217. What is the ratio of the secondary voltage to the primary voltage with the turn ratio in the windings? A. N/N B. (N/N22 C. (N/N2)\3 D. N, XN2
: A
233. The common-mode voltage gain is A. smaller than differential voltage gain B. equal to voltage gain C. greater than differential voltage gain D. None of the above
: A
238. This is an example of the output swing for a class amplifier. Power supply level A. A В. В C. AB D. C
: A
239. In a Colpitts oscillator, the frequency of oscillation when the quality factor decreases. A. Decreases B. Increases C. Remains the same D. Becomes erratic
: A
246. One condition for positive feedback is that the phase shift around the feedback loop must be A. O B. 90 C. 180 D. 45
: A
30. Famous transistor amplifier configuration designed to eliminate the so- called Miller effect. A. cascode amplifier B. darlington amplifier C. differential amplifier D. complementary-symmetry
: A
34. What is the difference between common-mode and differential-mode input signals? A phase relationship B. voltage C. current D. apparent power
: A
35. The primary function of the oscillator in an isolation amplifier is to A. convert dc to high-frequency ac B. convert dc to low-frequency ac C. rectify high-frequency ac to do D. produce dual-polarity dc voltages for the input to the demodulator
: A
36. This circuit is a oscillator. с с C >t 카 R Kärt R fran A. phase-shift B. Wien bridge C. Colpitts D. Hartley
: A
43. A portion of the output that provides circuit stabilization is considered to be: A. negative feedback B. distortion C. open-loop D. positive feedback
: A
49. Voltage amplifiers are operated as amplifiers. A. class A B. class B C. class C D. class AB
: A
50. Which of the following is a good practice in replacing capacitors in voltage multipliers? A. the replacement capacitors must have the same or higher voltage ratings than the originals B. reversing the capacitor polarity c. using a smaller value of capacitor but with higher voltage rating D. using a higher value of capacitor but with lower voltage rating
: A
51. What is the major advantage of the R/2R ladder digital-to-analog (DAC), as compared to a binary-weighted digital-to- analog DAC converter? A. It only uses two different resistor values. B. It has fewer parts for the same number of inputs. C. Its operation is much easier to analyze. D. The virtual ground is eliminated and the circuit is therefore easier to understand and troubleshoot.
: A
52. The ramp voltage at the output of an op- amp integrator A. increases or decreases at a linear rate B. increases or decreases exponentially C. is always increasing and never decreasing D. is constant
: A
53. How many leads does the TO-5 metal can package of an operational amplifier have? A, 8, 10, or 12 B. 6, 8, or 10 C. 8 or 14 D. 8 or 16
: A
56. The feedback signal in a(n) _________ oscillator is derived from an inductive voltage divider in the LC circuit. A. Hartley B. Armstrong C. Colpitts D. Crystal
: A
57. At series resonance, the impedance of a crystal is A. minimum. B. maximum. C. equal. D, zero.
: A
59. Direct coupling is used for amplification. A. very low frequency B. audio-frequency C. radio-frequency D. ultra high frequency
: A
60. To use a comparator for zero level detection, the inverting input is connected to A. ground B. a positive reference voltage C. the dc supply voltage D. a negative reference voltage
: A
63. Input impedance Zin of an inverting amplifier is approximately equal to: A. Ri B. R+ Ri C. D. Rr- Ri
: A
67. For frequencies up to 1 MHz, the is the most widely used type of sinusoidal RC oscillator. A. Wien-bridge B. phase-shift C. twin-T D. relaxation
: A
83. All of the following are basic op-amp input modes of operation EXCEPT A. inverting mode B. common-mode C. double-ended D, single-ended
: A
87. What is the typical value of quality factor for crystal oscillators? A. 20,000 B. 1000 C. 100 D. 10
: A
89. What is the purpose of a level shifter in op-amps? A. to set and/or adjust the output voltage to zero when the input signal is zero B. to set and/or adjust the input offset voltage to zero C. to shift the input offset current to zero D. all of the choices
: A
90. It is a differential voltage gain device that amplifiers the difference between the voltages existing at its two input terminals A. Instrumentation amplifier B. Specific instrumentation amplifier C. Isolation amplifier D. Difference amplifier
: A
95. In the classic three-op-amp instrumentation amplifier, the differential voltage gain is usually produced by the A. first stage B. second stage C. mismatched resistors D. output op-amp
: A
MALA 101. A data conversion system may be used to interface a digital computer system to: A. an analog output device B. a digital output device C. an analog input device D. a digital printer
: A
a 102. In order to sustain oscillations in feedback oscillator, the gain should be so the Act A. reduced, equals one B. reduced, is less than one C. increased, is more than one D. increased, is much greater than one
: A
a 19. A loading control in tuned power amplifier. A. provides an impedance match between the bipolar transistor or FET and the load B. allows broadband operation C. adjusts the resonant frequency D. controls the input impedance
: A
a two-state 213. The Schmitt trigger is device that is used for: A. pulse shaping B. peak detection C. input noise rejection D. filtering
: A
an 71. Which is not analog-to-digital (ADC) conversion error? A. differential nonlinearity B. missing code C. incorrect code D. offset
: A
decreases transistors 110. Increasing degeneration what undesirable effect in amplifiers? A. Thermal instability B. Junction heating C. Bias voltage increase D. Leakage current surge
: A
element of a 200. The feedback differentiator is A. Resistor B. Capacitor C. Inductor D. RC network
: A
error 9. refers to the term, remote sensing with regard to a linear voltage regulator A. The feedback connection to the amplifier is made directly to the load B. Sensing is accomplished by wireless inductive loops C. The load connection is made outside the feedback loop D. The error amplifier compares the input voltage to the reference voltage
: A
is an 221. digital-to-analog converter application of the A. scaling adder B. voltage-to-current converter C. noninverting amplifier D. adjustable bandwidth circuit
: A
is the power 78. Quiescent power dissipation of a transistor A. with no signal input. B. with no load. C. under full load. D. along the dc load line.
: A
is not a multivibrator. 104. A A. one-shot B. flip-flop C. VCO D. bistable
: A
operate with 136. Sinusoidal oscillators feedback. A. positive B. negative C. no D. one of the above
: A
the critical an 192. A series dissipative regulator is example of a: A. linear regulator B. switching regulator C. shunt regulator D. dc-to-dc converter
: A
to 164. The common-mode rejection ratio (CMMR) is the ratio of A. the differential voltage gain, the common-mode voltage gain B. the differential power gain, the common- mode power gain C. the ideal voltage gain, the actual voltage gain D. signal voltage, noise voltage
: A
1 48. The Q-point is at cutoff for class operation. A. A B. B C. C D. AB
: B
10. An operational amplifier must have at least how many usable terminals? A. 3 terminals B. 5 terminals C. 8 terminals D. 14 terminals
: B
105. The basic instrumentation amplifier has input(s). A. 1 B. 2 C. capacitive D. resistive
: B
112. The given circuit is a two-pole, active filter. 0.00€ 0.004 PEF 2.8 ko 2.8 ko Vout Vin 0.002 pF A. high-pass B. low-pass C. band-pass D. band-stop
: B
122. The input makes the summing amplifier possible. A. virtual ground at the noninverting B. virtual ground at the inverting C. low-voltage D. high-voltage
: B
126. This circuit is a oscillator. R +Vcc Output sinusoidal signal VEE A. phase-shift B. Wien bridge C. Colpitts D. Hartley
: B
13. An astable multivibrator is also known A, one-shot multivibrator B. free-running multivibrator C. bistable multivibrator D. monostable multivibrator
: B
131. The problems of the binary-weighted resistor digital-to-analog converter (DAC) can be overcome by using A. an 8-bit binary-weighted resistor DAC DAC B. an R2R ladder DAC C. a staircase DAC D. a flash DAC
: B
133. What is the output waveform of the circuit? 1 U 3 IDEAL_OPAMP Vout 1 mv 1000 Hz A. sine wave B. square wave C. sawtooth wave D. triangle wave
: B
135. The precision rectifier circuit is designed to A. rectify waveforms with very large voltage swings B. rectify waveforms with very smal voltage swings C. rectify precision waveforms D. amplify and rectify waveforms
: B
137. At parallel resonance, the impedance of a crystal is A, minimum. B. maximum. C. equal. D. zero.
: B
139. The tail of a diff amp acts like a A. Battery B. Current Source C. Transistor D. Diode
: B
144. The voltage required to differential output to Zero force the is called A. input-offset current B. input-offset voltage C, input bias current D. slew rate voltage
: B
16. At what phase shift is the magnitude of BA at its maximum in the Nyquist plot? A. 90° B, 180° C. 270° D. 0°
: B
161. The characteristic that a change of one binary step on the input of a digital-to- analog converter (DAC) should cause exactly one step change on the output is called A resolution B. monotonicity C. linearity D. accuracy
: B
166. In order to start up, a feedback oscillator requires A. negative feedback less than 1. B. positive feedback greater than 1. C. unity feedback equal to 1. D. no feedback.
: B
167. What is the relationship between the series and parallel resonant frequencies of a quartz crystal? A. They are equal. B. Parallel resonant frequency is approximately 1 kHz higher than series resonant frequency. C. Series resonant frequency is approximately 1 kHz higher than parallel resonant frequency. D. none of the above
: B
168. Which of the following instruments displays the harmonics of a distorted signal? A. Digital multimeter B. Spectrum analyzer C. Oscilloscope D. Wave analyzer
: B
172. The open-loop voltage gain (Ao) of an op-amp is the A. external voltage gain the device is capable of B. internal voltage gain the device is capable of C. most controlled parameter D. same as Ac
: B
177. An op-amp integrator has a square- wave input. The output should be A, a sine wave. B, a triangle wave. C. a square wave. D. pure dc.
: B
181. Sensor outputs destined for a digital computer system must first be processed by A, a DAC B, an ADC C. the MPU D. a PLD
: B
184. A virtual ground is a(n) ground because this point is at zero volts. A, ordinary B. voltage C. chassis D. earth
: B
185. If an operational transconductance amplifier (OTA) is used as an amplitude modulator, the voltage gain is varied by applying voltage to the input. A. demodulation, bias B. modulation, bias C. bias, modulation D. low-frequency, bias
: B
186. Refer to this figure. If CI increases in value, the resonant frequency will +Vcc R Vout R2 C2 200 pF TE C1 L2 50 MH Ooooh 10 ml A. increase. B. decrease. C. remain the same. D. none of the above
: B
188. This is an example of the output swing for a class amplifier. n 180° output swing OV A. A B. B C. AB D. C
: B
195. The amplifier is ideal for amplitude modulation since its gain is current-controlled. A. log B. operational transconductance C. isolation D. Schmitt
: B
199. The input signal for an instrumentation amplifier usually comes from alan A. Inverting amplifier B. Wheatstone bridge C. Transducer D. Differential amplifier
: B
203. If an op-amp has one input grounded and the other input has a signal feed to it, then it is operating as what? A. Common-mo B. Single-ended C. Double-ended D. Noninverting mode
: B
204. is NOT a characteristic of an ideal op-amp. A. Infinite voltage gain B. Minimum bandwidth C. Infinite input impedance D. Zero output impedance
: B
209. Which of the following L-type filters is the best bandstop filter? A. series resonant LC circuit in series with the load and parallel resonant LC circuit in shunt B. parallel resonant LC circuit in series with the load and series resonant LC circuit in shunt C. series resonant LC circuits in series and in parallel with the load D. parallel resonant LC circuits in series and in parallel with the load
: B
21. The practical use of binary-weighted digital-to-analog converters is limited to: A. R2R ladder DIA converters B. 4-bit DIA converters C. 8-bit DIA converters D. op-amp comparators
: B
211. A zero-level detector is a A. comparator with a sine-wave output B. comparator with a trip point referenced to zero C. peak detector D. limiter
: B
212. A noninverting closed-loop op-amp circuit generally has a gain factor: A. less than one B. greater than one C. of zero D. equal to one
: B
214. The given circuit is RE RI 2 ko Vout 630 mv Vin 30 mv A. an inverting amplifier B. a noninverting amplifier C. a voltage follower D. a differential amplifier
: B
216. What is the ratio of the output impedance with series feedback to that without feedback? A. 1 B. 1 + BA C. BA D. A
: B
22. Initially, the closed-loop gain (Adi) of a Wien-bridge oscillator should be A. Acl <3 B. Acı > 3 C. O D. Acl = 1
: B
223. When a capacitor is used in place of a resistor in an op-amp network, its placement determines: A. open- or closed-loop gain B, integration or differentiation C. saturation or cutoff D. addition or subtraction
: B
235. Filters with the characteristic are useful when a rapid roll- off is required because it provides a roll-off rate greater than -20/dB/decade/pole. A, Butterworth B. Chebyshev C. Bessel D. Flat
: B
245. A filter significantly attenuates all frequencies below fc and passes all frequencies above fc. A. low-pass B. high-pass C. band-pass D. band-stop
: B
248. What is the maximum efficiency of a class B circuit? A. 90% B. 78.5% C. 50% D. 25%
: B
250. Which of the following minerals provides the highest piezoelectric effect? A. Tourmaline B. Rochelle salt C. Quartz D. Diamond
: B
3. If ground is applied to the (+) terminal of an inverting op-amp, the () terminal will: A. not need an input resistor B. be virtual ground C. have high reverse current D. not invert the signal
: B
40. The amount of additional phase shift required to make the total phase shift around a closed loop equal to zero is called A. the unity-gain phase shift B. phase margin C. phase lag D. phase bandwidth
: B
45. Refer to figure below. This circuit is a setup for R, RL A. an antilog amplifier B. a constant-current source C. an instrumentation amplifier D. an isolation amplifier
: B
47. 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
: B
61. In a flash analog-to-digital converter, the output of each comparator is connected to an input of a: A. decoder B. priority encoder C. multiplexer D. demultiplexer
: B
64. A PLL can be used as a(n) A. series voltage regulator B. frequency multiplier C. relaxation oscillator D. Schmitt trigger
: B
70. To convert a summing amplifier to an averaging amplifier A. all inputs must be of the same value B. the ratio of RF / R must equal to the reciprocal of the number of inputs C. all input resistors must be of different value D. the ratio of Re / R must equal to the number of inputs
: B
72. A mathematical operation for finding the area under the curve of a graph is called A. differentiation B. integration C. curve averaging D. linear regression
: B
75. Circuits that shift the dc level of a signal are called A. limiters B. clampers C. peak detectors D. de converters
: B
76. For a phase-shift oscillator, the gain of the amplifier stage must be greater than A. 19 B. 29 C. 30 D. 1
: B
84. A circuit that has an output equal to the algebraic sum of the inputs is called a(n) A. integrator amplifier B. summing amplifier C. differential amplifier D. voltage multiplier
: B
85. The voltage gain of an OTA can be calculated using the formula RE A = A. R; A =gm RL B. (A. + 1 Av C. 2 RF Av R; D.
: B
D. 82. In the given circuit, if Rris reduced to 8 k92, the circuit becomes the 24 ka RE Vinio 24 ko 24 ko O +12V -ova zaka A. digital-to-analog converter B. averaging amplifier C. scaling adder D. summing amplifier with gain greater than unity
: B
a 220. What type of feedback is provided by a capacitor connected across the emitter- resistor in common emitter transistor amplifier? A. Bypassed B. Positive C. Negative D. Unbypassed
: B
a 225. Assertion (A): The maximum efficiency of a class B push pull amplifier is 78.5% Reason (R): A current mirror uses compensating diode in parallel with the emitter diode A. Both A and R are correct and Ris correct explanation for A B. Both A and R are correct but R is not correct explanation for A C. A is correct R is wrong D. A is wrong R is correct
: B
a as to 15. In shunt-shunt negative feedback amplifier, compared the basic amplifier A. both input and output impedances, decrease B. input impedance decreases but output impedance increase C. I/P impedance increases but OP impedance decreases D. both input and O/P impedance increases
: B
active filter 62. A two-pole high-pass would have a roll-off rate of A. 40 dB/decade B. -40 dB/decade C. 20 dB/decade D. -20 dB/decade
: B
as a: 14. An ideal amplifier should have: A. high input current B. zero offset C. high output impedance D. moderate gain
: B
at 97. The critical frequency is defined as the point which the response drops from the passband. A. -20 dB B. -3 dB C.-6 dB D. -40 dB
: B
103. With negative feedback, the returning signal A. is proportional to the output current B. is proportional to the differential voltage gain C. opposes the input signal D. aids the input signal
: C
108. By how much does the output signal vary for a class AB power amplifier? A. 360° B. 180° C. Between 180° and 360° D. Less than 180°
: C
109. If op-amp is used to amplify small ac- signals, what parameter you should greatly consider to ensure better performance? A. input bias circuit B. drift C. frequency response D. slew-rate
: C
11. What is the resolution of a digital-to- analog converter (DAC)? A. It is the comparison between the actual output of the converter and its expected output. B. It is the deviation between the ideal straight-line output and the actual output of the converter. C. It is the smallest analog output change that can occur as a result of an increment in the digital input. D. It is its ability to resolve between forward and reverse steps when sequenced over its entire range.
: C
111. analog-to-digital converters (ADCs) use no clock signal, because there is no timing or sequencing required. A. Actuator B. Dual C. Flash D. Bipolar
: C
114. An op-amp circuit in which the output voltage is equal to the difference between the two input voltages is called a(n) A. integrator B. differentiator C. differential amplifier D. voltage regulator
: C
116. Refer to this figure. This circuit is +Voc (4) (8) 100 n Ri RESET Vac DISCH (6) (3) THRESH soon R2 OUT (2) (5) TRIG CONT God 1 10 LF TCexe 19 (1) A, a sine-wave oscillator. B, a monostable multivibrator. C. an astable multivibrator, D. a VCO.
: C
117. In the Wien bridge oscillator, which of the following is (are) frequency- determining components? A. R1 and R2 B. Cl and C2 C. RI, R2, C1, and C2 D, None of the above
: C
124. The Q of a crystal A. is extremely low B. is about 40 or so in most cases C. is extremely high D. none of the above
: C
125. A Schmitt trigger is a comparator with A. modulation B. a closed-loop gain less than one C. hysteresis D. a high threshold value
: C
138. Which amplifier is commonly used as a frequency multiplier? A. class A B. class B C. class C D. all of the above
: C
140. What is the advantage of a push - pull amplifier as compared to a single transistor amplifier? A. Lower cost B. Fewer parts C. Higher gain D. Less power usage
: C
141. The number of binary bits at the input of a digital-to-analog converter (DAC) is known as A. accuracy B. linearity C. resolution D. monotonicity
: C
142. A Wien-bridge oscillator uses A. positive feedback B. negative feedback C. both types of feedback D. an LC tank circuit
: C
143. The ratio between differential gain and common-mode gain is called: A. amplitude B. differential-mode rejection C. common-mode rejection D. phase
: C
146. Which of the following is required for oscillation? A. BA>1 B. The phase shift around the feedback network must be 180°. C. Both BA >1 and the phase shift around the feedback network must be 180°. D. None of the above
: C
148. You find that there is no output signal. You measure the dc voltage of Q1 emitter and find it equal to 0 V. The trouble might be Vcc +20v R 1.2 ka ie 뜥 Q ce az so R2 1.2 ko A. Di is shorted. B. D2 is shorted. C. RI is open. D. no trouble, everything is normal.
: C
149. Which of the following components in a transistor amplifier circuit tends to limit the low frequency response of the amplifier? A. The transistor B. The load transistor C. The coupling capacitor D. The input signal developing resistor
: C
150. A filter that has a flat time delay in passband is A. Chevyshev filter B. Butterworth filter C. Bessel filter D. Elliptic filter
: C
152. An ideal operational amplifier has A. infinite output impedance B. zero input impedance C. infinite bandwidth D. All of the above
: C
155. The gain of an OTA is the ratio of the output current to the input voltage, and is measured in A. amps B. volts C. siemens D. no units
: C
158. A class B amplifier operates in the linear region for A. slightly more than 180° of the input cycle. B. 360° of the input cycle. C. slightly less than 180° of the input cycle. D. much less than 180° of the input cycle.
: C
160. The higher the order of the filter, the A. Higher the number of resistors B. Lesser the number of inductors C. Higher is the roll off D. Lower is the roll off
: C
163. If the input to a comparator is a sine wave, the output is a: A. ramp voltage B. sine wave C. rectangular wave D. sawtooth wave
: C
169. The power bandwidth increase is due to a A. Decrease in frequency B. An increase in voltage gain C. Decrease in peak voltage D. Decrease in initial slope
: C
170. The ratio of the center frequency to the bandwidth is known as A. Duty cycle B. Wideband factor C. Quality factor D. Narrowband factor
: C
176. This circuit is a oscillator. Voo yo RFC Cc RG HE C2 Cu ooooo A. phase- B. Wien bridge C. Colpitts D. Hartley
: C
178. You have an application for a power amplifier to operate on FM radio frequencies. The most likely choice would be a amplifier. A class A B. class B C. class C D. class AB
: C
179. An op amp has an open base resistor, the output voltage will be A. Zero B. Approaching to zero C. A maximum positive or negative D. An amplified sine wave
: C
193. The resistors Rf and Ri in an op-amp circuit control A. positive feedback and current gain B. negative feedback and power gain C. negative feedback and voltage gain D. open and closed loop gain
: C
194. Current cannot flow to ground through a(n) A. mechanical ground B. ac ground C. virtual ground D. virtual short
: C
198. Categorize the power efficiency of each class of amplifier, from worst to best. A. A, B, AB, D B. A, AB, D, B C. A, AB, B, D D. D, B, AB, A
: C
201. The Ic c formula shows that for a given capacitor, if the voltage changes at a constant rate with respect to time, the current will A. increase B. decrease C. be constant D. decrease logarithmically
: C
205. A voltage-to-current converter is used in applications where it's necessary to have an output load current that is controlled by A. input frequency B. output resistance C. input voltage D. input resistance
: C
207. The principal advantage(s) of BJTs over MOSFETs is (are) that A. voltage drop across the transistor is important. B. they are not as prone to ESD. C. both of the above D. none of the above
: C
224. An oscillator whose frequency can be controlled by an input "control voltage" is called a(n) A. PLL B. Schmitt trigger C. VCO D. S-R latch
: C
229. Which components provide the regenerative feedback signal in the phase- shift oscillator? A. Tapped inductor B. Tapped capacitor C. RC circuits D. Transformer
: C
23. With negative feedback, the returning signal: A. aids the input signal B. is proportional to output current C. opposes the input signal D. is proportional to differential voltage gain
: C
236. Refer to the given figure. This circuit is known as +Vcc RI 늘 Rz Cz L2 OOTORY हि I A, a Clapp oscillator. B. an Armstrong oscillator. C. a Colpitts oscillator. D. a Hartley oscillator.
: C
237. Which type of power amplifier is biased for operation at less than 180° of the cycle? A. Class A B. Class B or AB C. Class C D. Class D
: C
24. The magnitude of closed-loop voltage gain (Act) of an inverting amplifier equals: A. the ratio of the input resistance to the feedback resistance B. the open-loop voltage gain Aoi C. the feedback resistance divided by the input resistance D. the input resistance
: C
241. If the input to a comparator is a sine wave, the output is a A. ramp voltage B. sine wave C. rectangular wave D. sawtooth wave
: C
242. Decreasing the gain in the given circuit could be achieved by RE 200 ko Vout 3 V Vin 60 mv A. reducing the amplitude of the input voltage B. increasing the value of the feedback resistor C. increasing the value of the input resistor D. removing the feedback resistor
: C
243. An output that is proportional to the addition of two or more inputs is from which type of amplifier? A, differentiator B. difference C. summing D. analog subtractor
: C
27. The lead-lag circuit in the Wien-bridge oscillator has a resonant frequency at which the attenuation is A. 1/2. B. 1/4. C. 113. D. 1/5.
: C
31. The difference between analog voltage represented by two adjacent digital codes, or the analog step size, is the: A. quantization B. accuracy C. resolution D. monotonicity
: C
32. In an averaging amplifier, the input resistances are A. equal to the feedback resistance B. less than the feedback resistance C. greater than the feedback resistance D. unequal
: C
37. The start-up gain of an oscillator must be one. A. equal to B. less than C. greater than D. none of the above
: C
38. Which class of amplifier operates in the linear region for only a small part of the input cycle? A. A B. B C. C D. AB
: C
4. In a PLL, to obtain lock, the signal frequency must: A. come within the lock range B. be less than the capture frequency C. come within the capture range D. be greater than the capture frequency
: C
46. Refer to the given figure. The resonant frequency is controlled by +Vac Oooo L2 Ett C A. C3 and Ll. B. C2, C4, C5, and Li. C. C3, C4, C5, and L1. D. C3, C4, C5, and L2.
: C
5. This circuit is a setup for SER A, an antilog amplifier B. a constant-current source C. an instrumentation amplifier D. an isolation amplifier
: C
55. An instrumentation amplifier has a high A. output impedance B. power gain C. CMRR D. supply voltage
: C
58. How many transistors must be used in a class B power amplifier to obtain the output for the full cycle of the signal? A. O B. 1 C. 2 D. 3
: C
6. Only the condition BA = must be satisfied for self-sustained oscillations to result. A. O B. -1 C. 1 D. None of the above
: C
73. The closed-loop voltage gain of an inverting amplifier equals: A. the ratio of the input resistance to the feedback resistance B. the open-loop voltage gain C. the feedback resistance divided by the input resistance D. the input resistance
: C
80. What specification of an operational amplifier which tells how fast the output voltage can change? A. frequency response B. common mode rejection ratio C. slew rate D. open- loop voltage gain
: C
81. Sample-and-hold circuits in analog-to digital converters (ADCs) are designed to: A. sample and hold the output of the binary counter during the conversion process B. stabilize the comparator's threshold voltage during the conversion process C. stabilize the input analog signal during the conversion process sample and hold the DIA converter staircase waveform during the conversion process
: C
86. Which of the following is (are) the determining factor(s) of the stability of a feedback amplifier? A. A B. Phase shift between input and output signals C. Both A and the phase shift between input and output signals D. None of the above
: C
88. Which of the power amplifiers is not intended primarily for large-signal or power amplification? A. Class A B. Class B or AB C. Class C D. Class D
: C
93. A circuit whose output is proportional to the difference between the input signals is considered to be which type of amplifier? A. common-mode B. darlington C. differential D. operational
: C
96. What is the minimum frequency at which a crystal will oscillate? A. seventh harmonic B. third harmonic C. fundamental D. second harmonic
: C
98. Refer to this figure. This amplifier is operating as a amplifier. Voc +15V R. so ko Rc 2.2ko A. class A B. class B C. class AB D. class C
: C
99. The purpose of offset nulling is to A. reduce the gain B. equalize the input signals C. zero the output error voltage D. answers A and C
: C
a 175. The external resistor of typical instrumentation amplifier is used to set the A. impedance B. rejection ratio C. gain D. isolation
: C
a a 42. A triangular-wave oscillator can consist of an op-amp comparator, followed by a(n) A. differentiator B. amplifier C. integrator D. multivibrator
: C
a capacitive 106. The feedback signal in a(n) oscillator is derived from voltage divider in the LC circuit. A. Hartley B. Armstrong C. Colpitts D. Crystal
: C
an analog 151. An) input to a digital output. A. flash converter B. bipolar converter C. ADC D. DAC
: C
are 129. Which of the following the characteristics of a current shunt feedback? A. High input and low output impedance B. High input and high output impedance C. Low input and high output impedance D. Low input and low output impedance
: C
have 94. Switching voltage regulators than linear regulators. A. longer life B. simpler circuitry C. greater efficiency D. lower cost
: C
maximum power 20. The efficiency at transfer is equivalent to A. 100 % B. 90 % C. 50 % D. 0 %
: C
two 219. An audio oscillator using amplifiers in series (cascade) with positive feedback is A. a Colpitts circuit B. a Hartley circuit C. a multivibrator D. a VCO
: C
115. A Schmitt trigger has A. no trigger points B. one trigger point C. two trigger points D. three trigger points
: D
12. Comparator is an example of a(n) A. active filter B. current source C. linear circuit D. nonlinear circuit
: D
120. Which of the following types of coupling is usually used to couple the output from a power amplifier? A. RC B. Resistor C. Impedance D. Transformer
: D
121. analog-to-digital converters (ADCs) have a fixed value of conversion time that is not dependent on the value of the analog input. A. Substandard B. Dual C. Recessive approximation D. Successive approximation
: D
127. A certain oscillator has a tap on the inductor in the tank circuit. This oscillator is probably A. a Colpitts oscillator. B. a Clapp oscillator. C. a crystal oscillator. D. a Hartley oscillator.
: D
134. The 555 timer can be connected to operate a(n) A. astable multivibrator B. bistable multivibrator C. monostable multivibrator D. astable multivibrator and a monostable multivibrator
: D
145, A(n) amplifier is used if the application requires a high sensitivity to low-level signals and protection from high- voltage associated circuits. A, basic instrumentation B, operational transconductance C. log/antilog amplifier D. isolation
: D
154. If the input to a comparator is a sine wave, the output is a(n) A. ramp voltage B. sine wave C. sawtooth wave D. rectangular wave
: D
159. An operational amplifier has a A. Single ended input and single ended output B. Single ended input and differential output C. Differential input and differential output D. Differential input and single ended output
: D
17. What is the total phase shift requirement, around the feedback loop, for a phase-shift oscillator? A. 90° B. 180° C. 270° D. 360°
: D
174. The voltage gain of the amplifier in the given circuit would increase if RE Vout 630 mv RI 2 ko Vio 30 mv A. the feedback resistor was decreased in value B. the input voltage was increased C. the input resistor was increased in value D. None of the above
: D
18. Which of the following instruments allows more precise measurement of the harmonic components of a distorted signal? A. Digital multimeter B. Spectrum analyzer C. Oscilloscope D. Wave analyzer
: D
182. What is the output waveform? Ci Vin 3 1 Vout IDEAL_OPAMP 1 A. sine wave B. square wave C. sawtooth wave D. triangle wave
: D
187. Which of the following describe(s) a power amplifier? A. It can handle large power. B. It can handle large current. C. It does not provide much voltage gain. D. All of the above
: D
191. The center frequency of a band-pass filter is always equal to the A. bandwidth B. -3 dB frequency C. bandwidth divided by Q D. geometric average of frequencies
: D
197. The main features of a large-signal amplifier is the circuit's A. power efficiency B. maximum power limitations C. impedance matching to the output device D. All of the above
: D
2. A basic series regulator has A. an error detector B. a load C. a reference voltage D. both an error detector and a reference voltage
: D
202. What is this circuit? 유 it 3 Vin R2 Vout IDEAL_OPAMP I A. a low-pass filter B. a high-pass filter C. a bandpass filter D. a band-stop filter
: D
206. Which of the following oscillators is (are) tuned oscillators? A. Colpitts B. Hartley C. Crystal D. All of the above
: D
208. Which operation class is generally used in radio or communications? A. A В. В C. AB D. C.
: D
215. A filter rejects all frequencies within a specified band and passes all those outside this band. A. low-pass B. high-pass C. band-pass D. band-stop
: D
218. In a class AB amplifier, if the VBE drops are not matched to the diode drops or if the diodes are not in thermal equilibrium with the transistors, this can result in A, a current mirror. B. diode separation. C. crossover distortion. D. thermal runaway.
: D
222. In order for an output to swing above and below a zero reference, the op-amp circuit requires: A. a resistive feedback network B. zero offset C. a wide bandwidth D. a negative and positive supply
: D
226. Refer to the given figure. This circuit is known as R 0+Voc L2 oooo ca R2 R3 ca a + A. a Clapp oscillator. B. an Armstrong oscillator. C. a Colpitts oscillator. D. a Hartley oscillator.
: D
228. In practice, the efficiency of a capacitively coupled class A amplifier is about %. A. 25 B. 40 C. 70 D. 10
: D
230. If a current gain is desired, which of the following elements/networks should be used as an output coupling device? A. An RC network B. A resistive network C. A step up transformer D. A step down transformer
: D
232. Op-amps used as high- and low-pass filter circuits employ which configuration? A. noninverting B, comparator C. open-loop D. inverting
: D
234. The circuit in figure is D R А. rесtifier B. voltage to frequency converter C. frequency to voltage converter D. logarithmic amplifier
: D
240. The pulse width out of a one shot multivibrator increases when the A. Supply voltage increases B. Timing resistor decreases C. UTP decreases D. Timing capacitance increases
: D
244. When using an OTA in a Schmitt- trigger configuration, the trigger points are controlled by A. the lout B. the IBIAS C. the Vout D. both lout and IBIAS
: D
247. Class AB operation is ___________ operation. A. similar to class A B. similar to class B C. similar to class C D. None of the above
: D
25. The main drawback in the performance of shunt peaked wide band amplifier is A. two low gain at low frequency B. poor phase response C. reduce frequency at middle frequency D. that the maximum gain of the stage is small
: D
26. Which of the following improvements is (are) a result of the negative feedback in a circuit? A. Lower output impedance B. Reduced noise C. More linear operation D. All of the above
: D
28. What is the maximum efficiency of a class A circuit with a direct or series-fed load connection? A. 90% B. 78.5% C. 50% D. 25%
: D
29. Class D operation can achieve power efficiency of A 50 % B. 60 % C. 75 % D. 90 %
: D
39. For the same plate dissipation, the output power of a class B push-pull circuit is nearly that of a class A operation. A. 2 times B. 3 times C. 2.4 times D. 5 times
: D
41. The primary disadvantage of the flash analog-to digital converter (ADC) is that: A. it requires the input voltage to be applied to the inputs simultaneously B. a long conversion time is required C. a large number of output lines is required to simultaneously decode the input voltage D. large number of comparators is required to represent reasonable sized binary number
: D
44. A circuit that uses an amplifier with passive filter elements is called a(n): A. relaxation oscillator B. signal generator C. differential amplifier D. active filter
: D
54. The input offset current equais the A. average of two base currents B. collector current divided by the current gain C. difference between two base-emitter voltages D. difference between two base currents
: D
65. In an LC filter, the ripple factor, A. increases with load current B. increases with load resistance C. remains constant with the load current D. has the lowest value
: D
66. The attenuation of the three-section RC feedback phase-shift oscillator is A. 179. B. 1/30. C. 1/3. D. 1729.
: D
68. Which of the following is (are) power amplifiers? A, Class A B. Class B or AB C. Class C or D D. All of the above
: D
69. Which of the following transistors has been quite popular as the driver device for class D amplification? A. BJT B. FET C. UJT D. MOSFET
: D
7. At what phase shift is the magnitude of BA at its minimum in the Nyquist plot? A. 90° B. 180° C. 2700 D. 0°
: D
74. Common-mode signals have A. the same amplitude B. the same phase C. the same frequency D. All of the above
: D
79. One of the most versatile and widely used in electronic device linear applications. A. SCR B. FET C. UJT D. Op-amp
: D
8. The principal advantage(s) of MOSFETs over BJTs is (are) A. their biasing networks are simpler. B. their drive requirements are simpler. can in parallel for C. they be connected added drive capability. D. all of the above
: D
91. Which of the following characterizes an analog quantity? a curve. A. Discrete levels represent changes in quantity. B. Its values follow a logarithmic response C. It can be described with a finite number of steps. D. It has a continuous set of values over a given range.
: D
92. Above the critical frequency (fc) of a low-pass filter, the output voltage gain 1 KHz increase in A. does not change B. doubles for every frequency C. increases D. decreases
: D
MALA 171. Inaccurate analog-to-digital conversion may be due to A. constant analog input voltage B. linear ramp usage C. intermittent counter inputs D. faulty sample-and-hold circuitry
: D
MULTIPLE CHOICE QUESTIONS 1. Which of the following is a type of error associated with digital-to-analog converters (DACs)? A, nonmonotonic error B. incorrect output codes C. offset error D. nonmonotonic and offset error
: D
a free-running 33. What starts multivibrator? A, a trigger B. an input signal C. an external circuit D. nothing
: D
an 153. In open-loop op-amp circuit, whenever the inverting input (/) is negative relative to the noninverting input (+), the output will: A. swing negative B. close the loop C. be balanced D. swing positive
: D
an to 231. If the value of resistor Rf in averaging amplifier circuit is equal to the value of one input resistor divided by the number of inputs, the output will be equal A. the average of the individual inputs B. the inverted sum of the individual inputs C. the sum of the individual inputs D. the inverted average of the individual inputs
: D
are a 227. Class amplifiers normally operated in push-pull configuration in order to produce an output that is a replica of the input. A. A В. В C. C D. AB
: D
as an if you 147. Refer to this figure. Assuming it is configured oscillator and desired to reduce the duty to less than 50%, the following circuit change would need to be made. +Voc (4) (8) 1002 R RESET Voc (7) DISCH (6) (3) SOO Z Rz THRESH OUT (2) (5) TRIG CONT Gnd 10 F се (1) A. Reduce the size of Ri. B. Reduce the size of R2. C. Increase the size of RI. D. Connect a diode in parallel with Ri.
: D
following is (are) 157. Which of the feedback? A. Voltage-series B. Voltage-shunt C. Current-series D. All of the above
: D
in an 249. The kind of oscillator found electronic wristwatch is the A. Armstrong B. Clap C. Colpitts D. Quartz crystal
: D
must 210. For a circuit to oscillate, the gain must be high, the feedback must be positive, and A. the input must be a sine wave B. the power supply voltage be positive C. the device must use a bipolar JFET D. the coupling from output to input must be good
: D
name a unity gain 162. Another for amplifier is: A. difference amplifier B. comparator C. single ended D. voltage follower
: D
produces a 77. The twin-T oscillator response. A. low-pass B. high-pass C. band-pass D. band-stop
: D
t 118. Which type of amplifier uses pulse (digital) signals in its operation? A. Class A B. Class B or AB C. Class C D. Class D
: D
