教育
-Analog Electronics Technique-章节资料考试资料-Huazhong University of Science and Technology【】
Test questions for The Ideal Operational Amplifier
1、【单选题】The two input terminals of an operational amplifier are labeled as:
A、high and low
B、positive and negative
C、inverting and noninverting
D、differential and nondifferential
参考资料【 】
2、【单选题】For the circuit in the Figure, the output voltage vo is ( ).
A、-6V
B、-5V
C、-1V
D、-0.2V
参考资料【 】
3、【单选题】For the circuit in Figure, the current ix is ( )
A、0.6mA
B、0.5mA
C、0.2mA
D、1/12 mA
参考资料【 】
4、【单选题】For the circuit in Figure, current io is( )
A、-10 μA
B、-2.5 μA
C、10/12 μA
D、10/14 μA
参考资料【 】
5、【单选题】If vs=8 mV, in the circuit of Figure, the output voltage is( )
A、-44 mV
B、-8 mV
C、4 mV
D、7 mV
参考资料【 】
6、【单选题】The power absorbed by the 4k ohm resistor in Figure is( ).
A、9 mW
B、4 mW
C、2 mW
D、1 mW
参考资料【 】
7、【单选题】For the circuit in Figure,the output voltage v0 is( ).
A、3 V
B、-3 V
C、-1 V
D、-2 V
参考资料【 】
8、【单选题】For the circuit in Figure,the output current io is( ).
A、0.2 mA
B、-0.2 mA
C、0.1 mA
D、-0.1 mA
参考资料【 】
9、【单选题】For the circuit in Figure,the output voltage vo is( ).<img src="http://edu-image.nosdn.127.net/52330AF6793DC7306B1E1CDC53C688C5.png?imageView
A、5V
B、-5V
C、3.75V
D、-3.75V
参考资料【 】
10、【单选题】For the circuit in Figure,the output voltage vo is ( )
A、5 V
B、-5 V
C、8 V
D、-8 V
参考资料【 】
11、【单选题】For the circuit in Figure,the output voltage vo is ( ).
A、5 V
B、-5 V
C、3.8 V
D、-3.8 V
参考资料【 】
12、【单选题】Assume the operational amplifiers are ideal,if the input voltage is +1V，Determine vo=( ).
A、1 V
B、-1 V
C、2 V
D、0 V
参考资料【 】
13、【单选题】Assume the operational amplifiers are ideal,Determine vo=( );
A、1 V
B、-1 V
C、2 V
D、0 V
参考资料【 】
14、【单选题】For the circuit in Figure,the output voltage vo is( )
A、150 mV
B、250 mV
C、350 mV
D、450 mV
参考资料【 】
15、【单选题】For the circuit in Figure,the output voltage vo is( )
A、3.2 V
B、-0.8 V
C、2.4 V
D、1.2 V
参考资料【 】
16、【单选题】For the circuits shown as Figure, assume the op-amps is ideal, and the maximun output voltage of all of the op-amps is ±13V, when time is t=0s, give the input voltage is a step in voltage, and the amplitude of the input is 100mV, when time is t=1s, determine the output voltage of each op-amp is( ).
A、13 V
B、-13 V
C、0 V
D、100 mV
参考资料【 】
17、【单选题】For the circuit in the Figure, the op-amps are ideal, the input resistances of the two circuits are ( )<img src="http://edu-image.nosdn.127.net/32AA7704457CD8DF3B55EDC29B09C7E5.png?imageView
A、Ri1=Ri2=1k ohm
B、Ri1<Ri2
C、Ri1>Ri2
D、Ri1=Ri2=∞
参考资料【 】
18、【单选题】Assume all the Op-Amps are ideal, determine vo in terms of vi is （ ）
A、vo=-0.5(vi+5)
B、vo=0.5(vi+5)
C、vo=2(vi+5)
D、vo=-2(vi+5)
参考资料【 】
19、【单选题】Determine the voltage transfer ratio vo/vs in this op-amp circuit, where R=10k ohm.
A、-1/3
B、-2/3
C、1/3
D、2/3
参考资料【 】
20、【单选题】Assume all the Op-Amps are ideal, and when time t=0, the capacitor voltage vc=0, then when t=0, vo1=( ), vo2=( ).
A、vo1=4V,vo2=1V;
B、vo1=-4V,vo2=-1V;
C、vo1=7V, vo2=1V;
D、vo1=7V, vo2=-2V
参考资料【 】
21、【单选题】Assume all the Op-Amps are ideal, and when time t=0, the capacitor voltage vc=0, then when t=( ? )s, the output voltage vo=0.
A、1
B、1/70
C、1/35
D、2
参考资料【 】
22、【多选题】For an ideal op amp, which of the following statements are not true?
A、The differential voltage across the input terminals is zero
B、The current into the input terminals is zero.
C、The current from the output terminal is zero
D、The input resistance is zero
E、The output resistance is zero
参考资料【 】
23、【多选题】Difference amplifiers maybe used in ( ).
A、instrumentation amplifiers
B、voltage followers
C、buffers
D、summing amplifiers
E、subtracting amplifiers
参考资料【 】
24、【判断题】In the linear operational amplifiers circuit, the inverting input of the operational amplifier is virtual ground.
A、正确
B、错误
参考资料【 】
25、【判断题】The voltage gain of the voltage follower is 1, so it can be replaced by a wire.
A、正确
B、错误
参考资料【 】
26、【判断题】In the case of open-loop, the integrated operational amplifier must work in the non-linear region.
A、正确
B、错误
参考资料【 】
27、【填空题】Assume all the Op-Amps are ideal, determine vo is （ ）V.<img src="http://edu-image.nosdn.127.net/7C2E2D927BB1F5CC621E31F1A527CA8F.jpg?imageView
A、
参考资料【 】
Test questions for Semiconductor Materials and Diodes Circuits
1、【单选题】At room temperature, the concentration relationship between free electrons and holes in intrinsic semiconductors is as follows （ ）
A、Undetermined
B、More free electrons
C、More holes
D、Same
参考资料【 】
2、【单选题】What are the majority carriers in n-type materials?
A、holes
B、free electrons
C、Positive ions
D、Negative ions
参考资料【 】
3、【单选题】What are the minority carriers in p-type materials?
A、holes
B、free electrons
C、Positive ions
D、Negative ions
参考资料【 】
4、【单选题】After the formation of PN junction, the relationship between diffusion current and drift current is as follows （ ）
A、More diffusion current
B、More drift current
C、Same
D、Undetermined
参考资料【 】
5、【单选题】When PN junction is reverse biased, the resistance becomes （ ）
A、smaller
B、larger
C、Unchanged
D、Undetermined
参考资料【 】
6、【单选题】When the PN junction is forward biased , the current is mainly（ ）
A、Reverse drift current
B、Forward diffusion current
C、Forward drift current
D、Reverse diffusion current
参考资料【 】
7、【单选题】For the circuit shown in Figure， when Vγ=0.7V， the diode voltage VD and the current ID are （ ）
A、VD=0.7V, ID=1mA
B、VD=0.5V, ID=1mA
C、VD=0.5V, ID=0mA
D、VD=0.7V,ID=0mA
参考资料【 】
8、【单选题】When the temperture T increases， the forward voltage of the PN junction ( )
A、Increase
B、Decrease
C、unchanged
D、uncertain
参考资料【 】
9、【单选题】The concentration of the majority carriers in the extrinsic semiconductor is mainly affected by ( ).
A、The concentration of impurity
B、The temperature
C、The crystal defect
D、The doping technology
参考资料【 】
10、【单选题】The concentration of the minority carriers in the extrinsic semiconductor is mainly affected by ( )
A、The concentration of impurity
B、The temperature
C、The crystal defect
D、The doping technology
参考资料【 】
11、【单选题】The zener diode circuit is shown as figure, if VI =10V，R =100ohm，VZ =5V，IZ(min)=5mA，IZ(max)=50mA,T、then the reisitance of RL should be ( )
A、> 111 ohm
B、< 111 ohm
C、> 111 k ohm
D、< 111 k ohm
参考资料【 】
12、【单选题】The circuit is shown as figure, and VDD = 2 V，R = 1 kohm,vs=50sin(2pi50t)mV，and Vγ=0.7V, then the quiescent current of the diode is ( ), the quiescent voltage of the output vO is ( ) , and the ac voltage amplitude of the output is ( ) .
A、2mA，2V；0.05V
B、1.3mA，1.3V；0.05V
C、2mA，2V；0.049V
D、1.3mA，1.3V；0.049V
参考资料【 】
13、【单选题】The circuit is shown as figure, the input voltages are shown in the table, the output voltage should be ( )
A、a
B、b
C、c
D、d
参考资料【 】
14、【单选题】The circuit is shown as figure,the diodes are silicon diodes, when vs = 6sinwt V, please use the case1 model (Vr=0.7V) to analysis the circuit, the output waveform should be ( ) <img src="http://edu-image.nosdn.127.net/0AE209CA7D2B7F28E2B65490A78AF7B2.png?imageView<img src="http://edu-image.nosdn.127.net/C0CE68334196CEBBA95F882327314AA6.png?imageView
A、a
B、b
C、c
D、d
参考资料【 】
15、【单选题】The circuit is shown as figure , if the RMS value of the ac sine signal is 220V, RL = 0.1k,we use the ideal model to analysis the circuit, then the peak inverse voltage of the diode is ( ).The maximum rectified current of the diode is ( ).
A、220V，0.99A
B、220V，1.98A
C、311V，1.98A
D、311V，0.99A
参考资料【 】
16、【单选题】For the circuit shown as figure, if we use ideal model, and the amplitude of the ac sine signal is 24V, then the peak current of the diode is( ), and the peak inverse voltage of the diode is( ）
A、240mA，24V
B、120mA，12V
C、120mA，36V
D、360mA，36V
参考资料【 】
17、【单选题】The circuit is shown as figure,the diodes are silicon diodes, and Vr=0.7V, the diodes D1 and D2 should be ( ).
A、D1 on, D2 on;
B、D1 on, D2 off
C、D1 off, D2 off
D、 D1 off,D2 on
参考资料【 】
18、【单选题】The circuit is shown as figure, the load voltage is VL=9V, aand the input voltage maybe vary between 11 and 13.6V, the current of the load will vary from 0 to 100mA, the the maximum current of the zener diode is ( )
A、100mA
B、200mA
C、300mA
D、400mA
参考资料【 】
19、【多选题】In order to form n-type semiconductors, What elements can you add ( )
A、B
B、C
C、Al
D、Si
E、P
F、Ga
G、Ge
H、As
参考资料【 】
20、【多选题】In order to form p-type semiconductors, What elements can you add ( )
A、B
B、C
C、Al
D、Si
E、P
F、Ga
G、Ge
H、As
参考资料【 】
21、【判断题】For the actual diode, as long as the positive bias voltage is greater than zero, the diode will turn on.
A、正确
B、错误
参考资料【 】
22、【判断题】When using zener diodes, current limiting resistors are not required.
A、正确
B、错误
参考资料【 】
23、【判断题】For general diodes, LEDs and photodiodes, forward bias voltage is required for normal operation.
A、正确
B、错误
参考资料【 】
Test questions for The Field-Effect Transistor
1、【单选题】For a p-channel Enhancement-Mode MOSFET, to create an inversion layer,we must add what gate to source voltage VGS?
A、Positive
B、Negative
C、Arbitrary
D、Indeterminate
参考资料【 】
2、【单选题】The drain current of the MOSFET is formed by the ( ） drift movement ?
A、majority carrier
B、minority carrier
C、two carriers
D、Indeterminate
参考资料【 】
3、【单选题】The drain current of the MOSFET is controlled by the （ ）
A、the gate current iG
B、the gate to source voltage VGS
C、the darin to source voltage VDS
D、the gate to drain voltage VGD
参考资料【 】
4、【单选题】The drain current versus gate-to-source voltage characteristics is shown in Figure, the FET should be ( ).<img style=“width: 226px; height: 164px;” src="http://edu-image.nosdn.127.net/305C8FE50994F72AAB2B209AFD3DE0DB.png?imageView
A、Enhancement-mode NMOSFET
B、Enhancement-mode PMOSFET
C、Depletion-mode NMOSFET
D、Depletion-mode PMOSFET
参考资料【 】
5、【单选题】For the circuits shown in Figure, find which circuit can work as an amplifier ( ).
A、A
B、B
C、C
D、D
参考资料【 】
6、【单选题】The drain current versus gate-to-source voltage characteristics is shown in Figure， and for the MOSFET , the voltage of the three terminals are: VS=-5V,VG=1V,VD=3V, the work region of this MOSFET is ( ).<img style=“width: 218px; height: 146px;” src="http://edu-image.nosdn.127.net/A893E5151EC2A6049A87957AC7C7C34C.png?imageView
A、cutoff
B、saturation
C、nonsauration
D、Indeterminate
参考资料【 】
7、【单选题】The threshold voltage of the MOSFET in the circuit is VTN=1V, not consider the voltage drop of the drainresistor, Determine the work region of the MOSFET in the circuit. （ ）
A、cutoff
B、saturation
C、nonsauration
D、Indeterminate
参考资料【 】
8、【单选题】The threshold voltage of the MOSFET in the circuit is VTP=-1V, not consider the voltage drop of the drain resistor, Determine the work region of the MOSFET in the circuit. ( )
A、cutoff
B、saturation
C、nonsauration
D、Indeterminate
参考资料【 】
9、【单选题】In the circuit in Figure， VGSQ=（ ）V，ID=（ ）mA，VDS=( )V;
A、VGSQ=1V,IDQ=1mA,VDSQ=3V;
B、VGSQ=2V,IDQ=0.1mA,VDSQ=3V;
C、VGSQ=1V,IDQ=0.1mA,VDSQ=3V;
D、VGSQ=2V,IDQ=1mA,VDSQ=3V;
参考资料【 】
10、【单选题】In the circuit in Figure，the MOSFET worked in which Region? ( )
A、cutoff
B、saturation
C、nonsauration
D、Indeterminate
参考资料【 】
11、【单选题】In the circuit in Figure，the MOSFET worked in which Region? ( )
A、cutoff
B、saturation
C、nonsauration
D、Indeterminate
参考资料【 】
12、【单选题】In the circuit in Figure， VGSQ=（ ）V，ID=（ ）mA，VDS=( )V;
A、VGSQ=4V,IDQ=4mA,VDSQ=-2V;
B、VGSQ=4V,IDQ=1mA,VDSQ=7V;
C、VGSQ=3V,IDQ=1mA,VDSQ=6V;
D、VGSQ=4V,IDQ=1mA,VDSQ=3V;
参考资料【 】
13、【单选题】In the circuit in Figure， VGSQ=（ ）V，ID=（ ）mA，VDS=( )V;
A、VGSQ=4V,IDQ=4mA,VDSQ=-2V;
B、VGSQ=4V,IDQ=1mA,VDSQ=7V;
C、VGSQ=3V,IDQ=1mA,VDSQ=6V;
D、VGSQ=3V,IDQ=1mA,VDSQ=2.5V;
参考资料【 】
14、【单选题】In the circuit in Figure，the MOSFET worked in which Region? ( )
A、cutoff
B、saturation
C、nonsauration
D、Indeterminate
参考资料【 】
15、【单选题】In the circuit in Figure，the MOSFET worked in which Region? ( )
A、cutoff
B、saturation
C、nonsauration
D、Indeterminate
参考资料【 】
16、【单选题】In the circuit in Figure， VGSQ=（ ）V，ID=（ ）mA，VDS=( )V;
A、VGSQ=2V,IDQ=2mA,VDSQ=2.8V;
B、VGSQ=2.2V,IDQ=1mA,VDSQ=7.2V;
C、VGSQ=2V,IDQ=2mA,VDSQ=6V;
D、VGSQ=2.2V,IDQ=1mA,VDSQ=2.2V;
参考资料【 】
17、【多选题】Which MOSFETs can work as amplifiers in the following circuits.
A、A
B、B
C、C
D、D
E、E
参考资料【 】
18、【多选题】The gate source voltage and the drain source voltage are as follows, and VTN, VTP or VPN, VPP values are also known.which MOSFETs work in cutoff region （ ）
A、VDS＝3V， VGS＝2V， VTN＝1V
B、VDS＝3V， VGS＝1V， VTN＝1.5V
C、VDS＝3V， VGS＝－1V， VPN＝－2V
D、VDS＝－3V， VGS＝－2V， VTP＝－1V
E、VDS＝3V， VGS＝－2V， VTP＝－1V
F、VDS＝－3V， VGS＝－1V， VTP＝－1.5V
参考资料【 】
19、【多选题】The gate source voltage and the drain source voltage are as follows, and VTN, VTP or VPN, VPP values are also known.which MOSFETs work in saturation region （ ）
A、VDS＝3V， VGS＝2V， VTN＝1V
B、VDS＝3V， VGS＝1V， VTN＝1.5V
C、VDS＝3V， VGS＝－1V， VPN＝－2V
D、VDS＝－3V， VGS＝－2V， VTP＝－1V
E、VDS＝3V， VGS＝－2V， VTP＝－1V
F、VDS＝－3V， VGS＝－1V， VTP＝－1.5V
参考资料【 】
20、【判断题】For n-channel and p-channel MOSFETs, the drain source voltage VDS can be positive or negative value.
A、正确
B、错误
参考资料【 】
21、【判断题】For n-channel depletion-mose MOSFETs, the gate source voltage VGS must be positive in order to get the MOSFETs work in the saturation region.
A、正确
B、错误
参考资料【 】
22、【判断题】The threshold voltage of p-channel and n-channel enhancement-mode MOSFETs must be positive.
A、正确
B、错误
参考资料【 】
Test questions for Basic FET Amplifiers
1、【单选题】Assuming that the capacitors in the circuit are very large and can be regarded as short circuit to AC signal, the small signal equivalent circuit is （ ）?
A、
B、
C、
D、
参考资料【 】
2、【单选题】Assuming that the DC operating points of all the following amplifier circuits are normal, all of the capacitors to AC signal can be regarded as a short circuit, and the circuit with the largest input resistance is （ ）.
A、
B、
C、
D、
E、
参考资料【 】
3、【单选题】Assuming that the DC operating points of all the following amplifier circuits are normal, all of the capacitors to AC signal can be regarded as a short circuit, and which circuit has the lowest input resistance （ ）
A、
B、
C、
D、
E、
参考资料【 】
4、【单选题】Assuming that the DC operating points of all the following amplifier circuits are normal, all of the capacitors to AC signal can be regarded as a short circuit, and which circuit has the lowest output resistance （ ）
A、
B、
C、
D、
参考资料【 】
5、【单选题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit. The gm of T1 is gm=1mS.Determine the voltage gain of the circuit Av=vo/vi=（ ）
A、3.3
B、-3.3
C、-10
D、-0.77
参考资料【 】
6、【单选题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit. Determine the voltage gain of the circuit Av=vo/vi=（ ）
A、3
B、-3
C、6
D、-6
参考资料【 】
7、【单选题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit. Determine the voltage gain of the circuit Av=vo/vi=（ ）
A、3
B、-3
C、1
D、-1
参考资料【 】
8、【单选题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit. Determine the voltage gain of the circuit Av=vo/vi=（ ）
A、3
B、-3
C、6
D、-6
参考资料【 】
9、【单选题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit. Determine the voltage gain of the circuit Av=vo/vi=（ ）.
A、6
B、-6
C、2
D、-2
参考资料【 】
10、【单选题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit. Determine the voltage gain of the circuit Av=vo/vi=（ ）
A、3
B、-3
C、6
D、-6
参考资料【 】
11、【单选题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit. Determine the voltage gain of the circuit Av=vo/vi=（）.
A、-0.89
B、0.89
C、10
D、-10
参考资料【 】
12、【多选题】Assuming that the DC operating points of all the following amplifier circuits are normal, all of the capacitors to AC signal can be regarded as a short circuit, and which circuits have output and input signals in phase（ ）
A、
B、
C、
D、
E、
参考资料【 】
13、【多选题】Assuming that the DC operating points of all the following amplifier circuits are normal, all of the capacitors to AC signal can be regarded as a short circuit, and which circuits have output and input signals opposite phase（ ）
A、
B、
C、
D、
E、
参考资料【 】
14、【判断题】In the multistage amplifier circuit, the input resistance is the input resistance of the first stage, and the output resistance of the amplifier circuit is equal to the output resistance of the last stage (output stage).
A、正确
B、错误
参考资料【 】
15、【判断题】Because the voltage gain of common drain amplifier circuit is less than 1, it cannot be used in the amplifier circuit
A、正确
B、错误
参考资料【 】
16、【判断题】Because the structures of n-channel enhancement MOSFET and p-channel enhancement MOSFET are different, the DC bias of amplifier circuit is different, and the small model used in AC analysis is also different.
A、正确
B、错误
参考资料【 】
17、【判断题】The field effect transistor (FET) works in the saturation region and can be used as an amplifier. The AC amplification performance is independent of the DC operating point.
A、正确
B、错误
参考资料【 】
18、【判断题】The threshold voltage and transconductance of enhancement MOSFET are constant.
A、正确
B、错误
参考资料【 】
19、【填空题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit. The gm of T1 is gm=1mS.Determine the input resistance is（ ）kohm.
A、
参考资料【 】
20、【填空题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit.Determine the output resistance is ( ) ohm.
A、
参考资料【 】
21、【填空题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit.Determine the input resistance is ( )ohm.
A、
参考资料【 】
22、【填空题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit.Determine the source voltage gain of the circuit Av=vo/vs=( ).
A、
参考资料【 】
23、【填空题】The circuit is as shown in the figure, and the capacitance in the passband can be regarded as a short circuit.Determine the output resistance is ( )k ohm.
A、
参考资料【 】
Test questions for The Bipolar Junction Transistor
1、【单选题】When a BJT transistor is used as an amplifying device, the base-emitter junction is ( ) biased, and the base-collector junction is ( ) biased.
A、Forward，forward
B、Reverse, reverse
C、Forward, reverse
D、Reverse, forward
参考资料【 】
2、【单选题】For the impurity doping concentrations in the three regions of the BJT, which region is the highest ( )
A、base
B、emitter
C、collect
D、unidentified
参考资料【 】
3、【单选题】When a BJT transistor worked in saturation region, the base-emitter junction is ( ) biased, and the base-collector junction is ( ) biased.
A、Forward，forward
B、Reverse, reverse
C、Forward, reverse
D、Reverse, forward
参考资料【 】
4、【单选题】A transistor is biased in the forward-active mode, the current of the three terminals are I1= –1.2mA, I2= –0.03mA, I3= 1.23mA，which of these is the emitter terminal ( )，and which of these is the base terminal ( )
A、1，2
B、2，3
C、3,2
D、3,1
参考资料【 】
5、【单选题】In a BJT circuit, the transistor are made of silicon, and the voltage values for three terminals are given, which BJT operates in forward-active mode ( )
A、VC=6V ,VB=0.7V, VE=0V
B、VC=6V , VB=6V , VE=5.4V
C、VC=6V ,VB=4V ,VE=3.6V
D、VC=3.6V ,VB=4V ,VE=3.4V
参考资料【 】
6、【单选题】In a BJT circuit, the transistor are made of silicon, and the voltage values for three terminals are given, which BJT operates in cutoff region ( )（For silicon transistor，we think VBE（th）=0.5V）
A、VC=6V ,VB=0.7V, VE=0V
B、VC=6V , VB=6V , VE=5.4V
C、VC=6V ,VB=4V ,VE=3.6V
D、VC=3.6V ,VB=4V ,VE=3.4V
参考资料【 】
7、【单选题】In the amplification circuit, the BJT is worked in forward-active region, and the voltage of each terminals is V1=2V, V2=6V and V3=2.7V, for the three terminals, which is the emitter ( ), the type of this transistor is ( ).
A、3, NPN
B、2, PNP
C、1,NPN
D、1, PNP
参考资料【 】
8、【单选题】For the circuit shown in Figure, which region does the transistor work in ( )<img src="http://edu-image.nosdn.127.net/A0D65056EC3F64AAC7BAC21657C27FD0.png?imageView
A、Forward-active region
B、Saturation region
C、Cutoff region
D、unidentified
参考资料【 】
9、【单选题】For the circuit shown in Figure, which region does the transistor work in ( )
A、Forward-active region
B、Saturation region
C、Cutoff region
D、unidentified
参考资料【 】
10、【单选题】For the circuit shown in Figure, which region does the transistor work in ( )
A、Forward-active region
B、Saturation region
C、Cutoff region
D、unidentified
参考资料【 】
11、【单选题】For the circuit shown in Figure, if the input signal is a good sinusoidal signal, but the output waveform is in the Figure 16, so this is which distortion ( )
A、no distortion
B、Saturation region
C、Cutoff region
D、unidentified
参考资料【 】
12、【单选题】A transistor is biased in the forward-active mode, the current of the three terminals are I1= –1.2mA, I2= –0.03mA, I3= 1.23mA，the current gain β is ( )
A、30
B、40
C、50
D、60
参考资料【 】
13、【多选题】In a BJT circuit, the transistor are made of silicon, and the voltage values for three terminals are given, which BJT operates in saturation region ( )
A、VC=6V ,VB=0.7V, VE=0V
B、VC=6V , VB=6V , VE=5.4V
C、VC=6V ,VB=4V ,VE=3.6V
D、VC=3.6V ,VB=4V ,VE=3.4V
参考资料【 】
14、【多选题】For the circuit shown in Figure, if the input signal is a good sinusoidal signal, but the output waveform is in the Figure, so what measures can be taken to eliminate such distortion ( )
A、increase VCC amplitude
B、reduce the amplitude of signal source
C、reduce the value of load resistance RL
D、open the load
参考资料【 】
15、【判断题】If the emitter and collector of BJT transistor are exchanged, the amplifier can still be constructed.
A、正确
B、错误
参考资料【 】
16、【判断题】When NPN transistor works in the forward active region, generally we added positive power supply, but for PNP transistor, we must add negative power supply.
A、正确
B、错误
参考资料【 】
17、【填空题】For the circuit shown in Figure, the operational amplifier is assumed to be ideal, for the transistor VBE=VB-VE=0.7V, if the reading of the voltmeter is 200mV,then the current gain β of the transistor is ( )
A、
参考资料【 】
Test questions for Basic BJT Amplifiers
1、【单选题】 For the circuit shown in Figure, determine the small signal hybrid-π resistance rπ is ( )and the voltage gain is （ ）
A、2.6k ohm,200
B、2.6k ohm, -200
C、2.6 ohm, 200000
D、2.6 ohm, -200000
参考资料【 】
2、【单选题】For all of the circuits shown in Figure, which circuit can amplify AC small signal ( )
A、(a)
B、(b)
C、©
D、(d)
参考资料【 】
3、【单选题】For the circuit shown in Figure, which position is the switch in A, B, C? the transistor can work in the forward active region ( )
A、A
B、B
C、C
D、Unable to determine
参考资料【 】
4、【单选题】For the circuit shown in Figure, if the transistor works in the forward active region, which output waveform is correct ( )
A、
B、
C、
D、
参考资料【 】
5、【单选题】For the circuit shown in Figure, if the transistor works in the forward active region, which outputwaveform is correct ( )
A、
B、
C、
D、
参考资料【 】
6、【单选题】If the source resistance of the signal source is 1kohm，and when the amplifying circuit is not connected,the voltage amplitude of the signal source is 10mV， but when the amplifying circuit is connected,the voltage of the input port of the amplifying circuit is 8mV， then the input resistance of the amplifying circuit is ( )k ohm.
A、5
B、4
C、2
D、1
E、0.5
参考资料【 】
7、【单选题】For the amplifier, when the load is open,the output voltage is 4V, and when the 3k ohm load resistor is connected, the output voltage is 3V, then the output resistance of the amplification circuit is ( )k ohm.
A、5
B、4
C、2
D、1
参考资料【 】
8、【单选题】For the amplifier, when the input signal is 10pA current and the output is 500mV voltage, the input resistance of this amplifier is better if it is larger or smaller, and the the output resistance of this amplifier is better if it is larger or smaller( )
A、smaller,larger
B、smaller, smaller
C、larger, larger
D、larger, smaller
参考资料【 】
9、【单选题】For the circuit shown in Figure，the voltage gain is （ ）,and the input resistance is ( )k ohm, output resisdtance is ( ) k ohm.
A、145,300,1
B、-145, 0.69,2
C、290,0.69,2
D、-145,0.69,1
参考资料【 】
10、【单选题】For the circuit shown in Figure，the voltage gain is （ ）,and the input resistance is ( )k ohm, output resisdtance is ( ) k ohm.
A、87,1.55,3
B、-87, 1.55,3
C、174,1.55,1.5
D、-174,1.55,1.5
参考资料【 】
11、【单选题】For the circuit shown in Figure，when the 50uF capacitor is open, the the voltage gain is will ( ) and the input resistance will ( ), output resisdtance will ( ).
A、increase, decrease, unchanged
B、decrease, increase, unchanged
C、decrease,decrease,decrease
D、increase,increase,increase
参考资料【 】
12、【单选题】For the circuit shown in Figure ，the voltage gain is （ ）,and the input resistance is ( )k ohm, output resisdtance is ( ) ohm.
A、0.99,87.2,5.1k
B、0.99, 87.2, 33
C、0.99,260,2.55k
D、99,87.2,2.55k
参考资料【 】
13、【单选题】For the circuit shown in Figure，when the ouput voltage is Vo1, the source voltage gain Vo1/vs is （ ）,and the input resistance is ( )k ohm, output resisdtance is ( ) ohm.
A、0.79,82,2k
B、-0.79, 8.2, 2k
C、0.8,82,31
D、-0.8,8.2,1k
参考资料【 】
14、【单选题】For the circuit shown in Figure ，when the ouput voltage is Vo2, the source voltage gain is （ ）,and the input resistance is ( )k ohm, output resisdtance is ( ) ohm.
A、0.79,82,2k
B、-0.79, 8.2, 2k
C、0.8,8.2,31
D、-0.8,8.2,1k
参考资料【 】
15、【单选题】For the circuit shown in Figure，the voltage gain is （ ）,and the input resistance is ( )k ohm, output resisdtance is ( ) ohm.
A、-291,2.574,7.5k
B、291, 25, 7.5k
C、-291,0.025,7.5k
D、291,0.025,7.5k
参考资料【 】
16、【单选题】In the following circuits,which circuit has the least input resistance ( )
A、
B、
C、
D、
参考资料【 】
17、【单选题】In the following circuits,which circuit has the least output resistance.( )
A、
B、
C、
D、
参考资料【 】
18、【单选题】In the following circuits,which circuit has the largest absolute gain. ( )
A、
B、
C、
D、
参考资料【 】
19、【多选题】For the circuit shown in Figure, if the DC voltage VCE≈VCC, what may be wrong with the circuit?
A、The capacitor Cb1 is short
B、The resistor Rb is open
C、The resistor RC is short
D、The resistor Rb is short
E、The resistor RC is open
参考资料【 】
20、【多选题】For the circuit shown in Figure, if the transistor works in the forward active region, which small signal equivalent circuit is correct ( )
A、
B、
C、
D、
E、
F、
参考资料【 】
21、【多选题】Which of the following amplifying circuits may amplify the signal AC voltage ( )
A、CE
B、CC
C、CB
D、CS
E、CD
F、CG
参考资料【 】
22、【多选题】Which of the following amplifying circuits may amplify the signal AC current ( )
A、CE
B、CC
C、CB
D、CG
E、CD
F、CS
参考资料【 】
23、【多选题】In the following circuits,which circuits have output voltage and input voltage in phase.( )
A、
B、
C、
D、
参考资料【 】
24、【多选题】In the following circuits,which circuits have inverse output and input voltages.( )
A、
B、
C、
D、
E、
参考资料【 】
25、【判断题】When a BJT transistor is biased in the forward-active mode, then iC=β iB, so we can think oftransistors as always linear devices.
A、正确
B、错误
参考资料【 】
26、【判断题】Use the BJT, we can magnify an input small signal to a large output signal, we don’t need DC power supply.
A、正确
B、错误
参考资料【 】
27、【判断题】As long as the transistor works in the forward active region, no matter how large the input signal is, linear amplification can be realized.
A、正确
B、错误
参考资料【 】
28、【判断题】Because of the different structure of NPN and PNP, the DC biasing is different when they work in forward active region, so the small signal model is different
A、正确
B、错误
参考资料【 】
29、【判断题】The capacitor can be open for dc, and can be short for any signal frequency.
A、正确
B、错误
参考资料【 】
30、【判断题】The independent source can always become a short circuit for ac analysis.
A、正确
B、错误
参考资料【 】
31、【判断题】For the BJT, when the Early voltage VA is not infinite， we’re dealing with small-signal amplifiers, we also say that the collector current of a BJT in active mode is equal to the base current multiplied by β.
A、正确
B、错误
参考资料【 】
32、【判断题】For the circuit with emitter bypass capacitor, this bypass capacitor not only changes the Q-point, but also affects the small signal voltage gain.
A、正确
B、错误
参考资料【 】
33、【判断题】Because the small signal voltage gain of the common collector circuit is less than 1, it has no contribution to signal amplification.
A、正确
B、错误
参考资料【 】
34、【判断题】The common collector circuit can neither amplify voltage nor current.
A、正确
B、错误
参考资料【 】
35、【判断题】For the circuit shown in Figure ，whether the output voltage waveform is correct（ ）
A、正确
B、错误
参考资料【 】
Test questions for Frequency Response
1、【单选题】In a single stage common-emitter circuit, at the corner frequency of fH, the phase of voltage gain φ(f) is ( ) degree.
A、-45
B、-135
C、-180
D、-225
参考资料【 】
2、【单选题】If the frequency f is nearly zero , the voltage gain of the circuit is equal the pass-band voltage gain, then the circuit may be ( )
A、low-pass filter
B、high-pass filter
C、bandpass filter
D、band-reject filter
参考资料【 】
3、【单选题】Consider the circuit in the figure, what is the time constant τ associated with this circuit? and this circuit is high-pass circuit or low-pass circuit?
A、0.05s, high-pass
B、0.05s, low-pass
C、0.2s, high-pass
D、0.2s, low-pass
参考资料【 】
4、【单选题】Consider the circuit in the figure, what is the time constant τ associated with this circuit? and this circuit is high-pass circuit or low-pass circuit?
A、0.05s, high-pass
B、0.05s, low-pass
C、0.2s, high-pass
D、0.2s, low-pass
参考资料【 】
5、【单选题】The magnitude frequency response of an amplifier circuit is shown in the figure, so the upper corner frequency is （ ）, the lower corner frequency is （ ）, and the passband gain is （ ）.
A、100Hz，50000Hz，5dB
B、100Hz，50000Hz，5
C、100rad/s，50000rad/s，5
D、100rad/s，50000rad/s，5dB
参考资料【 】
6、【单选题】The transfer function corresponding to the Bode plot of the magnitude shown in figure,what is the actual gain at 100Hz.
A、60dB
B、57dB
C、40dB
D、63dB
参考资料【 】
7、【单选题】In high frequency range, drop in gain is caused by ( )
A、bypass capacitors
B、coupling capacitors
C、transistor’s parasitic capacitors
D、bias resistors
参考资料【 】
8、【单选题】When the signal frequency f is equal to the corner frequency fL or fH, the gain is ( ) times as big as the maximum midband gain.
A、0.5
B、0.707
C、0.9
D、1.414
参考资料【 】
9、【单选题】In a two-stage amplifier circuit, if 20log|AVM1|=40dB, and fL1=4Hz,fH1=20kHz,20log|AVM2|=30dB,fL2=400Hz，fH2=150kHz， the for the two-stage amplifier， the total voltage gain is （ ），and the lower corner frequency is （ ）， the upper corner frequency is （ ）
A、70， 4Hz，20kHz
B、70dB， 400Hz， 20kHz
C、70，400Hz， 20kHz
D、70dB， 4Hz， 150kHz
参考资料【 】
10、【单选题】Consider the circuit in the figure, what is the time constant τ associated with Cb1?
A、11ms
B、21ms
C、1ms
D、10ms
参考资料【 】
11、【单选题】Consider the circuit in the figure, what is the time constant τ associated with Cc?
A、8ms
B、4ms
C、2ms
D、10ms
参考资料【 】
12、【单选题】A zero of the transfer function T(s)=10*(s+1)/[(s+2)(s+3)] is at （ ）
A、10
B、-1
C、-2
D、-3
参考资料【 】
13、【单选题】On the Bode magnitude plot, the slope of 1/[(5+jw)(5+jw)] for large values of w is ( )
A、20dB/decade
B、40dB/decade
C、-20dB/decade
D、-40dB/decade
参考资料【 】
14、【单选题】The difference between the half-power frequencies is called the ( )
A、quality factor
B、resonant frequency
C、bandwidth
D、cutoff frequency
参考资料【 】
15、【多选题】In low frequency range, drop in gain is caused by ( )
A、bypass capacitors
B、coupling capacitors
C、transistor’s parasitic capacitors
D、bias resistors
参考资料【 】
16、【多选题】To find the maximum gain magnitude of the amplifier ( )
A、Coupling and bypass capacitors act as shorts
B、transistors’ junction capacitances act as opens
C、Coupling and bypass capacitors act as opens
D、transistors’ junction capacitances act as shorts
参考资料【 】
17、【多选题】In order to reduce the lower corner frequency of the circuit shown in the figure, and without changing the passband gain, the following measures can be taken ( )
A、increase Cb1,Cb2
B、increase Ce
C、decrease Cb1,Cb2
D、decrease Ce
E、increase Rc
参考资料【 】
18、【多选题】The poles of the transfer function T(s)=10(s+1)/[(s+2)*(s+3)] is at （ ）
A、10
B、-1
C、-2
D、-3
参考资料【 】
19、【判断题】The difference between direct coupled amplifier and RC coupled amplifier is that its gain in low frequency region will not be attenuated.
A、正确
B、错误
参考资料【 】
20、【判断题】The lower corner frequency of the amplifier circuit can be reduced by selecting the transistor with small junction capacitance.
A、正确
B、错误
参考资料【 】
21、【判断题】Bandwidth can be increased by reducing the gain of the amplifier circuit.
A、正确
B、错误
参考资料【 】
22、【判断题】Consider the circuit in the figure, if the 50uF bypass capacitor is connected to the circuit, then the bandwidth of this amplifier can be increased.
A、正确
B、错误
参考资料【 】
23、【判断题】Generally, the bandwidth of common gate and common base amplifier is wider than that of common source and common emitter amplifier.
A、正确
B、错误
参考资料【 】