智慧树知道模拟电子技术基础(西安邮电大学)-智慧树-知到-题库零氪作业答案查询

日期:2021-10-17 07:42:15

第一章测试

1、Which of the following is not a commonly used semiconductor material'? ( )
    A、carbon
    B、lead
    C、silicon
    D、germanium

2、The characteristic of an ideal diode are those of a switch that can conduct current( ) .
    A、in both directions
    B、in one direction only
    C、in both directions but in only one direction at a time
    D、depends on the circuit it is used in

3、When a diode is doped with either a pentavalent or a trivalent impurity its resistance will ( ) .
    A、increase
    B、decrease
    C、make the resistance stable against variation due to temperature

4、The piecewise linear model, equivalent circuit of the diode consists of ( ).
    A、a junction capacitor, a battery, a small resistor, and the ideal diode
    B、a battery, a small resistor, and the ideal diode
    C、a battery and the ideal diode
    D、the ideal diode

5、When a p-n junction is reverse-biased, its junction resistance is ( ).
    A、high
    B、low
    C、determined by the components that are external to the device
    D、constantly changing

第二章测试

1、What is the value of the voltage dropped across forward-biased silicon diodes that are connected in parallel with each other? ( ).
    A、11.3 V
    B、0.35 V
    C、0.7 V
    D、1.4 V

2、The resistor voltage and resistor current in this circuit are ( ). image.png
    A、10 V, 5 mA
    B、11 V, 2 mA
    C、11 V, 11 mA
    D、2 V, 11 mA

3、Which of the following circuits is used to eliminate a portion of a signal? ( ).
    A、Clipper
    B、Damper
    C、Voltage multiplier
    D、Voltage divider

4、The circuit shown here is a ( ). image.png
    A、series clipper
    B、parallel clipper
    C、series clamper
    D、shunt clamper

5、The Zener diode must be operated such that ( ).
    A、image.png
    B、image.png is less than the specified image.png
    C、the applied voltage is greater than image.png
    D、All of these

第三章测试

1、In the active region, the base-emitter junction ( ).
    A、and the base-collector junctions are both forward-biased
    B、and the base-collector junctions are both reverse-biased
    C、is forward-biased while the base-collector junction is reversed-biased
    D、is reverse-biased while the base-collector junction is forward-biased

2、A BJT has measured dc current values of image.png = 0.1 mA and image.png= 8.0 mA. When IB is varied by 100 μA, IC changes by 10 mA. What is the value of the βac for this device?( ).
    A、80
    B、10
    C、100
    D、800

3、When a BJT is operating in the active region, the voltage drop from the base to the emitter image.png is approximately equal to the ( )。
    A、base bias voltage
    B、base current times the base resistor
    C、diode drop (about 0.7 V)
    D、emitter voltage

4、BJTs are commonly used as ( ).
    A、the primary components in amplifiers
    B、series damper circuits
    C、the primary components in rectifiers

5、The condition where increase in bias current will not cause further increases in collector current is called ( ).
    A、cutoff
    B、saturation
    C、active operation

第四章测试

1、When a BJT is biased in the cutoff region the collector-to-emitter voltage is typically equal to ( ).
    A、the emitter voltage
    B、0.03 V
    C、the collector current times the collector resistor
    D、the collector supply voltage

2、Calculate the collector-emitter voltage for this emitter-stabilized circuit.( ) image.png
    A、4.32 V
    B、10.68 V
    C、0.1335 V
    D、14.24 V

3、The difference between the resulting equations for a network in which an npn transistor has been replaced by a pnp transistor is ( ).
    A、the values of the resistors
    B、the value of β
    C、the sign associates with the particular quantities

4、The term quiescent means ( ).
    A、midpoint-biased
    B、at rest
    C、active
    D、inactive

5、Voltage-divider bias stability is ( ).
    A、dependent on alpha
    B、dependent of beta
    C、dependent on the collector resistor
    D、independent of beta

第五章测试

1、Given this configuration, determine the input impedance if VS = 40 mV, Rsense = 0.5 kΩ, and the input current is 20 μA.( ) image.png
    A、1.5 MΩ
    B、5.822 MΩ
    C、1,500 Ω
    D、582 kΩ

2、The image.png transistor model replaces the ( ) with the junction diode's ac resistance.
    A、collector-base junction
    B、collector-emitter junction
    C、emitter—base junction

3、Calculate the voltage gain for this circuit. ( ) image.png
    A、-137.25
    B、-8.4
    C、-7.91
    D、-16.34

4、A transistor amplifier has an input signal applied to its emitter terminal and an output signal taken from its collector terminal. The amplifier is a(n) ( ).
    A、common-emitter amplifier
    B、common-base amplifier
    C、common-collector amplifier
    D、emitter follower

5、The voltage gain of a very well-designed common collector amplifier configuration, using a pnp transistor, is ( ).
    A、about -0.9
    B、about 0.9
    C、in the range 0.95 to 0.99
    D、in the range -0.95 to -0.99

第六章测试

1、Shockley's equation defines the ( ) of the FET and are unaffected by the network in which the device is employed.
    A、image.png characteristics
    B、drain characteristics
    C、input/output characteristics
    D、transfer characteristics

2、For an n-channel depletion MOSFET, image.png= 8 mA and image.png = -6 V. If image.png= 0.8 V, what is the value of the drain current, image.png? ( )
    A、8 mA
    B、10.25 μA
    C、10.28 mA
    D、6 mA

3、The region of the JFET drain curve that lies between pinch-off and breakdown is called ( ).
    A、the constant-voltage region
    B、the ohmic region
    C、the saturation region

4、In the family of FETs, you can expect to find ( ).
    A、an n-channel type
    B、a p-channel type
    C、unipolar structure

5、FETs usually ( ).
    A、are less sensitive to temperature change than BJTs
    B、have a higher input impudence than BJTs
    C、are smaller in construction than BJTs

第七章测试

1、This graphical solution represents ( ). image.png
    A、fixed bias for an n-channel JFET
    B、voltage-divider bias for an n-channel JFET
    C、self bias for an n-channel JFET

2、Generally, it is good design practice for linear amplifiers to have operating points that close to ( ).
    A、are close to saturation level
    B、the cut-off region
    C、the midpoint of the load line

3、Which of the following biasing circuits can be used with E-MOSFETs? ( )
    A、self bias
    B、zero bias
    C、drain-feedback bias
    D、current-source bias

4、The primary difference between JFETs and depletion-type MOSFETs is ( ).
    A、JFETs can have positive values of image.png and levels of drain current that exceed image.png
    B、depletion-type MOSFETs can have positive values of image.png and levels of image.png that exceed image.png
    C、depletion-type MOSFETs can have only positive of image.png
    D、JFETs can have only positive values of image.png

5、A JFET can be biased in several different ways. The common method(s) of biasing an n-channel JFET is(are) ( ).
    A、self-bias configuration
    B、voltage-divider bias configuration
    C、fixed-bias configuration

第八章测试

1、The FET version of the BJT's common-emitter configuration is the ( ) circuit.
    A、common-source
    B、common-gate
    C、common-drain
    D、common-current

2、Calculate the input impedance for this FET amplifier. ( ) image.png
    A、image.png
    B、image.png
    C、image.png
    D、image.png = would depend on the drain current image.png

3、Design this circuit for a voltage gain of 10. You have to calculate the value of resistor image.png and image.png. It is desired that the transistor operate with a relatively high value of image.png. For this device, a high value of image.png is defined as image.png. ( ) image.png
    A、image.png
    B、image.png
    C、image.png
    D、image.png

4、The ( ) amplifier has high input impedance, low output impedance, and low voltage gain.
    A、common-gate
    B、common-drain
    C、common-source

5、The ( ) FET amplifier has low input impedance, high output impedance, and high voltage gain.
    A、common-gate
    B、common-drain
    C、common-source

第九章测试

1、Calculate the low frequency break point due to the capacitor image.png for this BJT amplifier. ( ) image.png
    A、image.png
    B、image.png
    C、image.png
    D、image.png

2、If several identical stages of amplifiers, each having the exact same upper and lower cutoff frequencies, are connected in cascade, then the bandwidth of the resulting amplifier will ( ).
    A、increase
    B、remain unchanged
    C、decrease
    D、be equal to the sum of all the individual bandwidths

3、A 3-dB drop in β occurs at ( ).
    A、image.png
    B、image.png
    C、image.png
    D、image.png

4、Negative dB values represent ( ).
    A、power gain
    B、power losses
    C、power values that do not change

5、An amplifier has a midband power gain of 24,500. What is the value of the power gain in dB for the circuit? ( )
    A、87.78 dB
    B、43.9 dB
    C、4.39 dB

第十章测试

1、Under difference-mode operation, the difference-mode voltage gain for this circuit is ( ).image.png
    A、0.0397
    B、80
    C、40
    D、0.08

2、The operational amplifier will only slightly amplify signals ( ).
    A、when the supply voltages are more then ±25 V
    B、when the supply voltages are less then ±5 V
    C、that are common on both the inputs
    D、that are different on both the inputs

3、The inverting and noninverting inputs to an op-amp are used to drive a(n) ( ) amplifier.
    A、inverting
    B、noninverting
    C、differential
    D、open-loop

4、When a given op-amp has a common-mode input of 10 V, the output of the device is 10 V. When the device has a differential input of 2 mV, the output of the device is 10 V. What is the CMPR of the device? ( )
    A、5 : 1
    B、5000 : 1
    C、1000 : 1
    D、5,000,000 : 1

5、The bandwidth of an amplifier is ( ).
    A、the range of frequencies over which gain remains relatively constant
    B、the range of frequencies between the lower and upper 3 dB frequencies
    C、the range of frequencies found using image.png

第十一章测试

1、If the input voltage is 0.25 V and the output is -2.5 V, the value ofimage.png must be ( ). image.png
    A、40.0 kΩ
    B、20.0 kΩ
    C、16.0 kΩ
    D、5.0 kΩ

2、The output voltage, VO, is given by ( ). image.png
    A、image.png
    B、image.png
    C、image.png

3、A summing integrator is an op-amp integrator that has ( ).
    A、multiple feedback capacitors
    B、multiple input resistors
    C、multiple input resistors and feedback capacitors

4、A second order low-pass filter has a high-end roll-off of ( ).
    A、60 dB/octave
    B、40 dB/decade
    C、20 dB/octave
    D、6 dB/decade

5、An active filter that provides a constant output for input signals above image.png is called an ideal ( ).
    A、low-pass filter
    B、high-pass filter
    C、bandpass filter

第十二章测试

1、A class B amplifier (not push-pull) ( ).
    A、conducts through 360° of the input waveform
    B、conducts through 180° of the input waveform
    C、conducts between 180° and 360° degrees of the input waveform, depending on the amount of dc bias
    D、conducts through less than 180° of the input waveform

2、Crossover distortion in class B amplifiers is prevented by ( ).
    A、biasing the transistors deeply into cutoff
    B、biasing the transistors slightly above cutoff
    C、using complementary-symmetry transistors
    D、increasing the load resistance

3、The maximum theoretical efficiency of an RC-coupled class A amplifier is ( ).
    A、25%
    B、50%
    C、78.5%
    D、99%

4、Power amplifiers are typically used to drive low impedance loads.( )

5、The power that an amplifier delivers to a load is equal to the difference between the power that the circuit draws from the power supply and the power that the circuit dissipates.( )

第十三章测试

1、The feedback circuit connection shown here is ( ). image.png
    A、voltage series feedback
    B、voltage shunt feedback
    C、current series feedback
    D、current shunt feedback

2、Calculate the voltage gain for voltage series feedback when the amplifier gain is A = -2000 and F = -1/50. ( )
    A、-2000
    B、-1/50
    C、50
    D、-48.78

3、Calculate the input impedance for voltage series feedback when the amplifier has image.png = 10 kΩ, amplifier gain is A = -2000, and F= image.png. ( )
    A、input impedance with feedback 10 kΩ
    B、input impedance with feedback 410 kΩ
    C、input impedance with feedback 244 Ω
    D、input impedance with feedback 50 Ω

4、The output impedance of current-shunt feedback amplifier ( ) the output impedance of its op-amp.
    A、is increased when compared to
    B、is decreased when compared to
    C、is reduced by half when compared to
    D、has no effect on

5、An amplifier has a gain-bandwidth product of 200 MHz. A feedback network is added that has a feedback factor (1 + βA) of 18.88. What is the gain-bandwidth product for the circuit with the added feedback network? ( )
    A、10.59 MHz
    B、18.88 MHz
    C、200 MHz