* * * Total score of 25 questions: 100.
First, multiple-choice questions (* *15 questions, 60 points)
1.LC parallel network has resonance.
I. Capacitance
obstruction
C, sensibility
2. The reason for choosing the differential amplifier circuit is ().
A, overcome the temperature drift
B, improve the input resistance
C, stable delivery multiple
3. To convert sine wave voltage into frequency doubling voltage, you should choose
I. Inverse Proportional Operation Circuit
B. In-phase proportional operation circuit
C, integral operation circuit
D, power supply operation circuit
4. For Class A and Class B power amplifiers, the static operating point is generally set at () of the characteristic curve.
A, the middle of the amplification region
B. cut-off area
C, amplification area but close to the cut-off area
D, amplification area but close to saturation area
5. In order to get the current-voltage conversion circuit, it is necessary to introduce () into the amplifier circuit.
First, voltage series negative feedback
B, voltage parallel negative feedback
C, current series negative feedback
D, current parallel negative feedback
6. In the single-phase bridge rectifier circuit, if there is a rectifier connected in reverse, then
A, the output voltage is about 2UD.
B, become a half-wave DC.
C, rectifier tube will burn out due to excessive current.
7. It can be used to measure the DC resistance r of diode. When the power supply voltage e doubles in the figure, r will be ().
double portion
largen
C, unchanged
D, get smaller
8. The integrated operational amplifier has two inputs and () output.
a、 1
b、2
c、3
d、4
9. If you want to convert square wave voltage into triangular wave voltage, you should choose Aopeng Dongda.
I. Inverse Proportional Operation Circuit
B. In-phase proportional operation circuit
C, integral operation circuit
D, differential operation circuit
10. General integrated operational amplifier is suitable for amplification ().
First, the high frequency signal
B, low frequency signal
C, any frequency signal
1 1. In order to make the input resistance of the circuit high and the output resistance low, () should be introduced.
First, voltage series negative feedback
B, voltage parallel negative feedback
C, current series negative feedback
D, current parallel negative feedback
12. The main difference between power amplifier circuit and voltage amplifier circuit is ().
A, the former is higher than the power supply voltage of the latter.
B. The voltage amplification coefficient of the former is larger than that of the latter.
C, the former is more efficient than the latter
D, there is no difference
13. As a low-frequency amplifier, the integrated operational amplifier should choose ().
First, the general type
B, high resistance type
C, high-speed type
D, low power consumption type
14. The terminal voltage of the forward biased diode increases by 5%, and the current flowing through the diode ().
I. An increase of about 5%
B, the increase is less than 5%
C, an increase of more than 5%
D, basically unchanged
15. The reason why the complementary output stage of integrated operational amplifier adopts * * * connection mode is ().
I. Frequency bandwidth
B, strong ability to amplify voltage
C, strong load capacity
D, large input resistance
Second, true or false (* *10, 40 points)
1. The voltage magnification of an integrated operational amplifier without feedback circuit is called open-loop voltage magnification.
A. mistakes
B, correct
2. The rectifier circuit can convert sinusoidal voltage into pulsating DC voltage.
A. mistakes
B, correct
3. In the LC sine wave oscillation circuit, the reason why the general integrated operational amplifier is not used as an amplifier circuit is that its upper limit cut-off frequency is too low.
A. mistakes
B, correct
4. If the two threshold voltages of the lag comparator are the same as those of the window comparator, their output voltage waveforms are the same when their input voltages are the same.
A. mistakes
B, correct
5. Single-limit comparator has stronger anti-interference ability than hysteresis comparator, and hysteresis comparator has higher sensitivity than single-limit comparator.
A. mistakes
B, correct
6. As long as positive feedback is introduced into the circuit, sine wave oscillation will definitely occur.
A. mistakes
B, correct
7. Current and voltage outputs in the amplifier circuit are provided by active components.
A. mistakes
B, correct
8. Whether the parameters of differential amplifier circuit are ideal or not, RE has * * * mode negative feedback.
A. mistakes
B, correct
9. Because when RC series-parallel frequency selection network is used as feedback network, φ f = 0 and φ a = 0 of single-tube amplifier circuit meet the phase condition of sine wave oscillation φ a+φ f = 2nπ (n is an integer), a sine wave oscillation circuit can be formed by connecting them reasonably.
A. mistakes
B, correct
10. When the input voltage UI and the load current IL change, the output voltage of the voltage stabilizing circuit is absolutely unchanged.
A. mistakes
B, correct