Electrical Version Quiz Activity (True/False) at the End of 2015

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This post was last edited by jennifer12580 on 2015-12-24 at 10:25. Type: Year-end quiz activity. Period: December 16–20. Selection: The user with the highest number of correct answers will be named No.1 and receive 100 wealth points plus 5 charm points; No.2 will get 80 wealth points plus 3 charm points; No.3 will receive 50 wealth points plus 1 charm point. Lucky prizes: One winner will be chosen from each of the “Dashboard” and “Electrical” categories within the valid floors, receiving 20 wealth points each. Please have the section moderators keep track of this. (Second edit, no statistics!) The irrigation content shall be deleted directly! ）@yuchenchf 01. When a three-phase load is connected in Y (star) configuration, the current in the neutral wire is always zero. ( × )02. Pressure instruments should be installed in locations that are easy to observe and maintain. (√)03. The greater the resistivity of a conductive material, the better its conductivity. (×)04. The more digits after the decimal point in the measurement value, the more precise the measurement. (×)05. When the selected unit is the same, the more decimal places there are in the measurement value, the more precise the measurement. (√)06. The more decimal places retained in the calculation result, the higher the precision. (×)07. All non-zero digits in the measurement data are significant figures. (√)08. The smaller the time constant of the control system, the faster the response speed of the controlled variable, which in turn enhances the stability of the control system. (×)09. When measuring liquid pressure, the pressure gauge should be installed at the lower part of the pipeline; when measuring gas pressure, it should be installed at the upper part of the pipeline. (√)10. Zeros between non-zero digits are significant figures. (√) 11. For controlled objects with large pure lag, differential control can be introduced to improve control quality. (×)12. Zeros to the right of the decimal point whose integer part is not zero are significant figures. (√)13. A short circuit in the coil part of a dynamic temperature gauge will cause the gauge pointer to move slowly. (√)14. The wiring resistance of the thermoresistor should include the thermoresistor itself. (×)15. When someone gets an electric shock, they should be immediately removed from the power source and taken to the hospital for treatment. (×)16. Differential pressure transmitters can only measure liquid levels. (×)17. The temperature measurement range of thermocouples is wider than that of thermal resistors. (√)18. When the pressure to be measured is higher than atmospheric pressure, it is led into the bulb-shaped container of the single-tube manometer. (√)19. To ensure uniform pressure along the circumference before and after the orifice plate and obtain a more accurate differential pressure, an annular chamber is commonly used for pressure measurement in orifice plate design. (√) 20. Electromagnetic flowmeters cannot be used to measure the flow rate of gaseous media. (√)21. For the connection between the thermal resistor and the bridge circuit, the three-wire connection method should be preferred, as this helps to reduce errors caused by changes in the resistance of the connection wires. (√)22. In an electronic potentiometer bridge, if the supply voltage is below the rated value, the reading will be high; if the supply voltage is above the rated value, the reading will be low. (√)23. Under normal circumstances, when an electronic potentiometer changes its range, neither the compensation resistor nor the current-limiting resistor in the bridge circuit needs to be recalculated or adjusted. (√)24. If the level gauge indicates fluctuations around “zero” for an extended period, then the actual material level must also be near the lower limit of the material level. (×)25. The citation error is the ratio of the absolute error to the measured value, expressed as a percentage. (×)26. Errors caused by improper installation of instruments are systematic errors. (√)27. The accuracy of a instrument refers to the maximum allowable value of the basic error, that is, the basic error limit. (√)28. After calibrating the mechanical and electrical zero points of the galvanometer using a calibrated electronic potentiometer, it can be adjusted during use. (×)29. A multimeter can measure resistance with the circuit powered on. (×) 30. In automatic control systems, according to the different forms of the set values, they can be classified into constant-value control systems, follow-up control systems, and program control systems. (√) 31. A thermistor thermometer consists of a thermistor, a display instrument, and connection wires, with the connection wires using a three-wire connection method. (√)32. The “three-phase five-wire” power supply system refers to “three phase wires, one neutral wire, and one ground wire”. (√)33. Electromagnetic flowmeters cannot measure the flow rate of gaseous media. (√)34. The various DC voltages required in a circuit can be obtained through transformation using transformers. (×)35. For controlled objects with large pure lag, differential control can be introduced to improve control quality. (×)36. In a resistive circuit, whether it is in series or parallel, the total power dissipated in the resistors is equal to the power output by the power source. (√)37. Transformers are used to reduce voltage. (×)38. Electrical equipment usually needs to be grounded, which means connecting the enclosure to the neutral wire. (×)39. Connecting a capacitor in a resistive load circuit can compensate for and improve the power factor; this results in a reduction of the total current in the circuit, thereby reducing the apparent power and saving electrical energy. (×)40. Reducing the voltage at the generator side using a step-down transformer can minimize energy losses in the transmission lines. (×) According to the statistics, the winners of this event are as follows: No. 1 – 100 wealth points + 5 charm points @zjzcl168; No. 2 – 80 wealth points + 3 charm points @zhushuai; No. 3 – 50 wealth points + 1 charm point @ssln123, @machunyan0115. Lucky prize: +20 wealth points @zjp. Congratulations to all the winners! Please let @yuchenchf present the awards to them