[Chongqing Guangdong education] electronic circuit homework question bank of RTVU secondary school

1. Basic knowledge resistor is one of the most widely used circuit components .
A. correct
B. error
correct
right key ： Query on the left
Student answer ：A
2. A four-color ring resistor , The resistance value is determined by the number of the third color ring , If orange , Then the multiple is _______.
A.100 times
B.10000 times
C.10 times
D.1000 times
error
right key ： Query on the left
Student answer ：B
3. An adjustable resistance is marked as 504, The resistance value shall be _______.
A.50k
B.5M
C.500k
D.50M
correct
right key ： Query on the left
Student answer ：C
4. Inductors are divided into fixed inductors according to the change of inductance 、 Variable inductor 、 Fine tuning inductors, etc .
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
5. Marking method of inductor and resistor 、 The marking method of capacitors is the same , There is a direct scaling method 、 Character symbol method and color code method .
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
6. When the resistance of the measured coil is infinite , Indicates that the coil is partially short circuited .
A. error
B. correct
error
right key ： Query on the left
Student answer ：B
7. frequently-used CW78×× Series is a positive voltage output ,CW79×× Series is a negative voltage output .
A. correct
B. error
correct
right key ： Query on the left
Student answer ：A
8. The accuracy grade of multimeter is generally divided into 0.1、0.5、1.5、2.5、5 Wait a few levels .
A. correct
B. error
correct
right key ： Query on the left
Student answer ：A
9. Photodiodes are good or bad , Use a multimeter R×1k Block measurement , Its forward resistance is about 10kΩ.
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
10. Photosensitive resistance is made of the photoconductive properties of semiconductors , It's a junction free device .
A. correct
B. error
error
right key ： Query on the left
Student answer ：B
11. The pins of the integrated circuit are 3,5,7,8,10,12,14,16 Roots and so on .
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
12. External heating electric soldering iron is made of soldering iron head 、 Soldering iron heart 、 Shell 、 Wooden handle 、 Power leads 、 Plug and other parts .
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
13. When welding the element of the trap , Such as the lead pin of large electrolytic capacitor 、 Metal chassis grounding lug, etc , Should be selected 100W The above electric soldering iron .
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
14. When the electric soldering iron is not in use , Do not power on for a long time , To prevent damage to the soldering iron .
A. correct
B. error
error
right key ： Query on the left
Student answer ：B
15. The noise during welding can sometimes be as high as ______db, Have an impact on the human body .
A.100
B.120
C.30
D.150
correct
right key ： Query on the left
Student answer ：A
16. Necessary access shall be maintained at the welding operation site , The width of vehicle access shall not be less than _______ rice .
A.2
B.3
C.5
D.4
error
right key ： Query on the left
Student answer ：B
17. The melting point is 450℃ The above is called soft solder .
A. error
B. correct
error
right key ： Query on the left
Student answer ：B
18. The welding time should not be too long , It is best to use... For each solder joint 2s Time for welding , The continuous welding time shall not exceed 10s.
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
19. After final assembly of the parts ______ Carry out whole machine commissioning , Ensure that the technical indicators of the whole machine fully meet the design requirements .
A. must do
B. arbitrarily
C.ABC Three can
D. Can I?
correct
right key ： Query on the left
Student answer ：A
20. The fixing methods of components on the printed board are divided into horizontal and vertical .
A. correct
B. error
correct
right key ： Query on the left
Student answer ：A
21. Before commissioning after the installation of printed circuit board and other components or the whole machine , Must be in ______ Under the circumstances , Make a careful inspection , In order to find and correct installation errors , Avoid possible circuit damage caused by blind power on .
A. Turn it on and off
B. arbitrarily
C. Electrify
D. No electricity
correct
right key ： Query on the left
Student answer ：D
22. The new technology of printed board has ： Photo technology 、 Electronic engineering CAD、 Inkjet system .
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
23. For metal high-power tubes 、 Transformer and other components with large weight , The welding of pins is enough to support the weight of components .
A. error
B. correct
error
right key ： Query on the left
Student answer ：B
24. In order to obtain a voltage with small unidirectional pulsation , When the load current is small , With little change , Optional ______.
A.LCπ Type filtering
B.ABC All possible
C.RCπ Type filtering
D.LC wave filtering
error
right key ： Query on the left
Student answer ：B
25.2、 The technical index of regulated power supply is the parameter that represents the performance of regulated power supply , What are the two ______.
A. Characteristic index 、 Quality indicators
B. Series index 、 Characteristic index
C. Parallel index 、 Characteristic index
D. Series index 、 Quality indicators
correct
right key ： Query on the left
Student answer ：A
26. In single-phase bridge rectifier circuit , Average value of output voltage UO And the effective value of secondary side voltage of transformer U2 Should satisfy ______ Relationship .
A.U0=1、2U2
B.U0=1、0U2
C.U0=1、4U2
D.U0=0、9U2
error
right key ： Query on the left
Student answer ：A
27. The purpose of filter circuit in DC regulated power supply is ______.
A. Turn high frequency into low frequency
B. Change DC to AC
C. Filter out the AC component in the AC / DC mixture
D. Change AC to DC
error
right key ： Query on the left
Student answer ：A
28. The voltage stabilizing circuit in the voltage stabilizing power supply adjusts the element and load according to the voltage RL Which two types of voltage stabilizing can be divided according to the different link modes ______.
A. DC regulated power supply 、 regulated power supply
B. DC regulated power supply 、 Parallel voltage stabilizing circuit
C. regulated power supply 、 Series voltage stabilizing circuit
D. Parallel voltage stabilizing circuit 、 Series voltage stabilizing circuit
correct
right key ： Query on the left
Student answer ：D
29. Static V1 Tube base voltage UBQ1 Approximately by the power supply Vcc and （R1+RP1） And R2 The partial pressure ratio is determined , Therefore, the first stage amplifier is often called partial voltage emitter bias amplifier circuit , It can effectively stabilize the static working point of the amplification circuit .
A. correct
B. error
correct
right key ： Query on the left
Student answer ：A
30. In the basic amplifier circuit , The signal passing through the transistor has ______.
A. AC and DC components are
B. DC components
C. Communication components
D. Collector stage circuit
error
right key ： Query on the left
Student answer ：C
31. The first technical index to be considered for voltage amplification circuit is ______.
A. The voltage gain of the amplifier circuit
B. The working efficiency of the pipe
C. The voltage of the amplification circuit decreases
D. No distortion problem
error
right key ： Query on the left
Student answer ：D
32. Description of basic operation steps of circuit test ： Install the power supply → Check the welding quality of each component → Power on test → Clean up the site .
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
33.OTL The power amplifier circuit consists of an excitation amplifier stage and a power amplifier output stage .
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
34. The amplifier that provides low-frequency power to the load is called low-frequency power amplifier , abbreviation “ Power amplifier ”.
A. correct
B. error
correct
right key ： Query on the left
Student answer ：A
35. Install the transformer on the plywood 、 switch 、 Fuse and other components , Connect the power lead and the AC input terminal of the circuit board . Check the welding quality
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
36. The trigger pulses of two thyristors of single-phase half controlled bridge rectifier circuit shall be different in turn ______ degree .
A.60°
B.360°
C.180°
D.120°
correct
right key ： Query on the left
Student answer ：C
37.V5、R2、R3、R4、RP、C A relaxation oscillator comprising a single junction transistor .
A. error
B. correct
error
right key ： Query on the left
Student answer ：A
38. Single junction transistor model ： Yes BT33 and BT35 Two kinds of .
A. correct
B. error
correct
right key ： Query on the left
Student answer ：A
39. Because the circuit is directly connected with 220V Connect , Pay attention to safety during commissioning , Prevent electric shock .
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
40. When the potentiometer rotates counterclockwise , The light bulb gradually dimmed .
A. correct
B. error
error
right key ： Query on the left
Student answer ：A
41. basic RS The trigger consists of a NOR gate G1、G2 form .
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
42.RS The characteristic equation of the trigger is ：Qn+1=S+RQn The constraint is ：RS＝0
A. correct
B. error
correct
right key ： Query on the left
Student answer ：A
43. The logic function of a trigger can be represented by a truth table 、 Karnaugh map 、 Characteristic equation 、 State diagram and waveform diagram, etc 5 There are two ways to describe .
A. correct
B. error
correct
right key ： Query on the left
Student answer ：A
44. Here's the picture , When the button is pressed SB after , Power supply by V2 Yes C2 Charge .

A. error
B. correct
error
right key ： Query on the left
Student answer ：B
45. Use a multimeter to check whether there is a short circuit in the power supply , Insert the integrated circuit after no error , Before power on test .
A. error
B. correct
correct
right key ： Query on the left
Student answer ：B
46. The principle of intuitive method in the maintenance of electronic circuits is ______.
A. The intuitive method is a maintenance method to judge the fault by measuring the resistance value of each component at the first level of electrical integrated circuit with the ohm gear of multimeter .
B. Intuitive method is a maintenance method to find faults through human eyes or other sensory organs .
C. Intuitive method is to find faults through human eyes or other sensory organs 、 A maintenance method for troubleshooting .
D. Intuitionistic method is a maintenance method to judge faults through human eyes or measuring electrical integrated circuits with Ohm gear of multimeter .
error
right key ： Query on the left
Student answer ：A
47. Measure the circuit voltage of each stage of the amplifier , First, start with the power circuit components of this level , Usually the voltage _________ All indicate that the circuit is faulty .
A. Too large or too small
B. Too high or too low
C. Too heavy or too light
D. Too high or too large
correct
right key ： Query on the left
Student answer ：B
48. Resistance method is one of the most basic methods for troubleshooting , generally speaking , The resistance method has “ On-line ” Resistance measurement and measurement “______” There are two methods of resistance measurement .
A. Desoldering
B. Shift welding
C. welding
D. Electric welding
error
right key ： Query on the left
Student answer ：C
49._______ It is a detection method to judge the fault by measuring the working voltage of electronic circuits or components and comparing it with the normal value .
A. Voltage method
B. Desoldering method
C. Current method
D. Resistance method
correct
right key ： Query on the left
Student answer ：A
50. When detecting electronic circuits by current method , You can quickly find the heat of the transistor 、 Causes of heating of power transformer and other components , It is also a common means to detect the working state of tubes and integrated circuits . When detecting by current method , Often need ______ circuit .
A. To break off
B. binding
C. Connect
D. Hold fast
correct
right key ： Query on the left
Student answer ：A