When replacing a power supply， what MUST the technician observe？（）A、voltageB、currentC、wattageD、resistance
When replacing a power supply， what MUST the technician observe？（）
- A、voltage
- B、current
- C、wattage
- D、resistance
相关考题：
A technician is testing a power supply for correct output voltages at the HDD power connector.Which of the following voltages should the technician expect for a correctly working power supply?() A.6VB.9VC.12VD.24V
A technician is installing a new power supply into a computer. One of the power supply connectors that the technician needs to connect to the motherboard is square and contains 4-pins. This connector is known as which of the following?（）A.SATAB.FDDC.IDED.ATX
A technician suspects the AC voltage into a PC power supply is bad. Which of the following toolswould MOST likely be used to confirm the diagnosis?() A. MultimeterB. OscilloscopeC. Cable testerD. Power supply tester
Whenreplacingapowersupply,whatMUSTthetechnicianobserve?() A.voltageB.currentC.wattageD.resistance
When a grounding strap is not available, a technician can ground by touching the computer’s:() A. power supply.B. CPU fan.C. memory chips.D. motherboard.
材料：The field current supply in older machines comes from a lower voltage direct current generator or exciter on the same shaft as the alternator. Modern machines however are either statically excited or of the high-speed brush-less type. The exciter is required to operate to counter the effects of power factor for a given load. The power factor is a measure of the phase difference between voltage and current and is expressed as the cosine of the phase angle. With a purely resistance load the voltage and the current are in phase, giving a power factor of one. The power consumed is therefore the product of voltage and current. Inductive or capacitive loads, combined with resistance loads, produce lagging or leading power factors which have a value less than one.The power consumed is therefore the product of current, voltage and power factor. The alternating current generator supplying a load has a voltage drop resulting from the load. When the load has a lagging power factor this voltage drop is considerable. Therefore the exciter, in maintaining the alternator voltage, must vary with load current and also the power factor. The speed change of the prime mover must also be taken into account.问题： The word “machines” in the passage refers to _____.A.the direct current generatorB.the alternating current generatorC.the exciterD.the prime moverWhich of the following statements is true according to the passage ?A.With a purely resistance load, the power factor is zeroB.Inductive loads combined with resistance loads produces leading power factorsC.Capacitive loads combined with resistance loads produces lagging power factorsD.With a purely resistance load, the phase angle is zeroWhen the load has a lagging power factor this voltage drop is considerable. This sentence means that _____.A.with a purely resistance load, the voltage drops too muchB.there is a considerable voltage drop in the capacitive load combined with resistance loadC.when the load is the capacitive load combined with resistance load, the voltage drops to zeroD.when the load is the inductive load combined with resistance load, the voltage drop is fairly largeThe exciter must vary with: ① load current ② the power factor, ③ speed change of the prime mover.A.①B.②C.①②D.①②③请帮忙给出每个问题的正确答案和分析，谢谢！
When a grounding strap is not available, a technician can ground by touching the computer’s:（）A、power supply.B、CPU fan.C、memory chips.D、motherboard.
If a technician suspects that the voltage being delivered to a desktop computer’s power supply is insufficient or incorrect, which device should be used to determine the correct voltage?（）A、A power supply testerB、A multimeterC、A loopback adapterD、A cable tester
Which of the following should the technician do FIRST when replacing a motherboard?（）A、Use a benchmarking toolB、Use anti-static wrist bandC、Remove the CPUD、Remove the power supply
A technician does not have power to a PC. Which of the following tools should the technician use to check for electricity?（）A、Cable testerB、Power supply testerC、Tone generatorD、Multimeter
A technician receives a computer for repair and observes that the fan on the power supply is not moving. Which of the following should the technician do？ （）A、Move the power supply voltage switch to 220 volts.B、Add an additional fan to help cool the computer.C、Replace the cable that attaches the power supply to the motherboard.D、Replace the power supply.
A customer has a p650 on order and plans to put it in a current OEM rack. They are concerned that the p650 power supply may demand more current than the OEM PDU can provide. Which planning guide specification would provide the necessary requirements？（）A、VoltageB、FrequencyC、Power Source Loading （max）D、Power Source Loading （typical）
A technician is testing a power supply for correct output voltages at the HDD power connector. Which of the following voltages should the technician expect for a correctly working power supply?（）A、6VB、9VC、12VD、24V
A customer states their computer was fine until yesterday when they heard a pop noise and thecomputer stopped working. Which of the following components should the technician test FIRST?（）A、Main system boardB、ProcessorC、Hard disk driveD、Power supply
The technician has replaced a power supply with an identical power supply, and now the high end graphics card is not working. Which of the following should the technician check?（）A、The memoryB、The CMOS batteryC、The PCIe power jackD、The processor for chip creep
A technician suspects the AC voltage into a PC power supply is bad. Which of the following toolswould MOST likely be used to confirm the diagnosis?（）A、MultimeterB、OscilloscopeC、Cable testerD、Power supply tester
A technician has just installed a new power supply into a desktop computer and now the computer will not turn on. Which of the following is the MOST likely cause?（）A、The voltage selector switch on the power supply is set incorrectly.B、The 3.3v power line is connected to the wrong input on the motherboard.C、The new power supply voltage rating is too high.D、The 12v power cord is installed incorrectly.
A technician is installing a new power supply into a computer. One of the power supply connectors that the technician needs to connect to the motherboard is square and contains 4-pins. This connector is known as which of the following?（）A、SATAB、FDDC、IDED、ATX
When replacing a laptop keyboard, the FIRST thing that Bob, a technician, should do is remove:（）A、the battery.B、the memory cover and memory sticks giving access to the screws holding the keyboard in place.C、the top bezel covering the screws holding the keyboard in place.D、the AC power.
A technician arrives in Germany and discovers that when their PC is plugged into the outlet, nopower is received. Which of the following actions should the technician take to get the PC tooperate?（）A、Change the BIOS settings to the local timeB、Adjust the voltage selector switchC、Attach a 220 volt power strip from the current region to the PCD、Attach a 120 volt battery backup power supply to the PC
单选题A technician does not have power to a PC. Which of the following tools should the technician use to check for electricity?（）ACable testerBPower supply testerCTone generatorDMultimeter
单选题Which statement concerning reserve sources of energy for GMDSS is FALSE（）.AWhile the ship is at sea，there must be available at all times a supply of electrical energy sufficient to operate the radio installations and to charge any batteries used as part of a reserve source of energyBBoth the VHF and MF/HF installations must be simultaneously suppliedCA means of ensuring a continuous supply of electrical power must be provided to all GMDSS equipment that could be affected by an interruption in powerDIf a UPS or equivalent is used to supply power to the ship's GPS receiver or other source of positional information，a means must be provided to ensure the continuous supply of the information in the event of a failure to the ship's main or emergency source of power
单选题When replacing a power supply， what MUST the technician observe？（）AvoltageBcurrentCwattageDresistance
单选题When replacing a laptop keyboard, the FIRST thing that Bob, a technician, should do is remove:（）Athe battery.Bthe memory cover and memory sticks giving access to the screws holding the keyboard in place.Cthe top bezel covering the screws holding the keyboard in place.Dthe AC power.
单选题If a technician suspects that the voltage being delivered to a desktop computer’s power supply is insufficient or incorrect, which device should be used to determine the correct voltage?（）AA power supply testerBA multimeterCA loopback adapterDA cable tester
单选题A technician has just installed a new power supply into a desktop computer and now the computer will not turn on. Which of the following is the MOST likely cause?（）AThe voltage selector switch on the power supply is set incorrectly.BThe 3.3v power line is connected to the wrong input on the motherboard.CThe new power supply voltage rating is too high.DThe 12v power cord is installed incorrectly.
单选题A technician suspects the AC voltage into a PC power supply is bad. Which of the following toolswould MOST likely be used to confirm the diagnosis?（）AMultimeterBOscilloscopeCCable testerDPower supply tester