【单选题】
(71515)( )制动多用于位能要求限速运行的场合，此时电磁转矩与转动方向相反，对电机起制动作用。[322110204](1.0分)___
A. 反接
B. 能耗
C. 回馈
D. 电磁抱闸
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相关试题
【单选题】
(71516)额定电流为100 A的晶闸管，最大允许通过( )的恒定直流电流。[223110211](1.0分)___
A. 100 A
B. 117 A
C. 41 A
D. 157 A
【单选题】
(71517)车辆正常运行时，KP-2A型供电装置直流输出电压正常值应为( )。(1.0分)___
A. 24 V
B. 36 V
C. 45 V
D. 59 V
【单选题】
(71518)能耗制动时在同样转速下通入定子的直流电流越大制动作用越强，但过大会使定子绕组发热，通常为电动机空载电流的( )。[222120235](1.0分)___
A. 1～2倍
B. 2～3倍
C. 3～4倍
D. 4～5倍
【单选题】
(71519)为使直流电动机反转，应采取( )的措施来改变主磁场的方向。[223110206](1.0分)___
A. 改变励磁绕组极性
B. 减少电流
C. 增大电流
D. 降压
【单选题】
(71520)25T型客车的可编程控制器(简称PLC)供电后，绿色PWR灯亮，橙色RUN灯亮，红色( )灯灭；连接触摸屏或网关后橙色COM灯闪烁。[233110214](1.0分)___
A. FH
B. XS
C. ERR
D. ZD1
【单选题】
(71521)直流伺服电动机实质上就是一台( )直流电动机。[221110235](1.0分)___
A. 他励式
B. 串励式
C. 并励式
D. 复励式
【单选题】
(71522)对于或门来讲，其输入、输出关系为( )。[232110214](1.0分)___
A. 有1出1
B. 有0出0
C. 全1出1
D. 全1出0
【单选题】
(71523)半控桥式整流电路带电感负载时必须加上续流二极管是为了( )。[322110213](1.0分)___
A. 增大输出直流电压
B. 减少输出直流电压
C. 防止晶闸管不能导通
D. 防止电路失控
【单选题】
(71524)运用客车中轴温报警器同车同侧轴温显示温差不超过( )(1.0分)___
A. 2 ℃
B. 3 ℃
C. 4 ℃
D. 5 ℃
【单选题】
(71525)并励、他励电动机具有硬机械特性，这种特性特别适用于当负载变化时要求转速( )的场合。[222110235](1.0分)___
A. 绝对稳定
B. 比较稳定
C. 不太稳定
D. 极不稳定
【单选题】
(71526)在电力电子装置中，电力晶体管一般工作在( )状态。[321110211](1.0分)___
【单选题】
(71527)国家规定，直流电机从空载(不允许空载电机从1/4负载开始)到额定负载的所有情况下，电机的火花等级不超过( )级。[322110235](1.0分)___
【单选题】
(71528)机械性火花通常呈黄色，火星长，强度弱，而电气性火花通常呈( )，当电机的工作状态和负载条件变化时，火花的大小和亮度也随着明显的变化。[222110635](1.0分)___
【单选题】
(71529)测量电气设备的吸收比，应使用( )。[212110230](1.0分)___
A. 万用表
B. 直流双臂电桥
C. 兆欧表
D. 钳流表
【单选题】
(71530)要想测量高频脉冲信号，应选用( )。[222110214](1.0分)___
A. 简易示波器
B. SB-10型通用示波器
C. 同步示波器
D. 任何一种示波器均可
【单选题】
(71531)示波器中扫描发生器产生的是( )。[212110214](1.0分)___
A. 锯齿形波信号
B. 正弦波信号
C. 矩形波信号
D. 三角波信号
【单选题】
(71532)( )适用于电路试验、整机维修、晶体管参数测量等。[223110215](1.0分)___
A. 电机匝间耐压检测仪
B. 接触电阻检测仪
C. 晶体管测试仪
D. 数字测速仪
【单选题】
(71533)25T型客车检修规程对于H23XJD型电空阀泄漏试验规定，将风压调至900 kPa，电压调为( )时，用防锈检漏剂检查电空阀风路及各部须无泄漏。[311110204](1.0分)___
A. DC 48 V
B. AC 48 V
C. DC 77 V
D. AC 77 V
【单选题】
(71534)( )电压表是利用被测电压与不断递减的基准电压进行比较，通过比较最终获得被测电压数字量，然后用显示器显示出被测电压值。[222110232](1.0分)___
A. 电压-时间变换型
B. 电压-频率变换型
C. 逐次逼近比较型
D. 模拟型
【单选题】
(71535)J5型发电机的额定功率为( )。(1.0分)___
A. 2 kW
B. 3 kW
C. 5 kW
D. 8 kW
【单选题】
(71536)按仪表( )分类，可分为电压表、电流表、功率表、频率表等。[222110229](1.0分)___
A. 工作原理
B. 测量对象
C. 工作电流
D. 使用方法
【单选题】
(71537)我国规定安全电压额定值等级为( )。[223110409](1.0分)___
A. 36 V，24 V，12 V，6 V
B. 42 V，36 V，24 V，12 V，6 V
C. 42 V，36 V，12 V
D. 36 V，12 V，6 V
【单选题】
(71538)绝缘材料的型号规定以四位数表示，其中左起第( )数字表示绝缘材料的分类。[212110204](1.0分)___
【单选题】
(71539)主管段长和车间主任未按规定在“车统—181”上签字不超过2次的，在运用客车质量鉴定中属于管理部分( )问题。(1.0分)___
【单选题】
(71540)△形接法的三相笼形电动机若误接成Y形，那么在额定负载下运行时，其铜耗和温升将会( )。[232110235](1.0分)___
A. 减小
B. 增大
C. 不变
D. 视具体情况而定
【单选题】
(71541)当异步电动机的定子电源电压突然降低为原来电压的80％的瞬间，转差率维持不变，其电磁转矩将会减少到原来的电磁转矩的( )。[233110235](1.0分)___
A. 80％
B. 70％
C. 64％
D. 50％
【单选题】
(71542)电机转子不平衡，会使电机运行时发生振动和噪声，加速( )磨损，缩短电机的使用寿命。[212110235](1.0分)___
A. 轴承
B. 风扇
C. 转子铁芯
D. 密封圈
【单选题】
(71543)转子的不平衡量，可用( )表示。[221110235](1.0分)___
A. 偏心距
B. 重径积
C. 平衡精度
D. 偏心距，重径积和平衡精度
【单选题】
(71544)画放大电路的交流通道时，电容和直流电源可认为是( )。[232110206](1.0分)___
A. 开路，短路
B. 短路，开路
C. 开路，开路
D. 短路，短路
【单选题】
(71545)调试可控硅整流装置是( )。[232110213](1.0分)___
A. 先调主回路，后调控制回路
B. 先调控制回路，后调主回路
C. 控制回路与主回路同时调试
D. 先调主回路或先调控制回路均可
【单选题】
(71546)多谐振荡器是( )触发器。[232110215](1.0分)___
A. 无稳定
B. 双稳态
C. 单稳态
D. 单结晶体管
【单选题】
(71547)集成运算放大器由输入级，( )基本部分组成。[222110215](1.0分)___
A. 输出级两个
B. 中间级，输出级三个
C. 偏置电路，输出级三个
D. 中间级，输出级和偏置电路四个
【单选题】
(71548)同步电机按运行方式和功率转换方式，可分为( )。[231110235](1.0分)___
A. 发电机，电动机
B. 发电机，补偿机
C. 发电机，电动机，补偿机
D. 电动机，补偿机
【单选题】
(71549)( )是造成发电机端电压低的原因。[232110235](1.0分)___
A. 电机转速高于额定值
B. 励磁分流电阻断路
C. 电刷接触面积小压力不足
D. 剩磁消失
【单选题】
(71550)三相桥式整流电路(不带滤波器)，变压器副边电压有效值为24 V时负载上的直流电压应为( )。[232110213](1.0分)___
A. 21.6 V
B. 10.8 V
C. 56.1 V
D. 47 V
【单选题】
(71551)J5型发电机的额定输出电流为( )。(1.0分)___
A. 48 A
B. 60 A
C. 75 A
D. 85 A
【单选题】
(71552)物理方法制冷是运用物质的( )变化来实现的。[322110204](1.0分)___
【单选题】
(71553)温度、压力和比容三个参数是制冷剂的( )状态的基本参数。[323110204](1.0分)___
【单选题】
(71554)运行、检修及交接记录填写错误或漏项不超过3处的，在运用客车质量鉴定中属于管理部分( )问题。(1.0分)___
【单选题】
(71555)摄氏温标t，又叫国际百度温标，单位是( )。[312110204](1.0分)___
推荐试题
【单选题】
An administrator attempts to migrate a suspended virtual machine to a newly deployed vSphere 6.x cluster. The compatibility check fails. What condition could cause this behavior?___
A. The new vSphere 6.x cluster is running Intel CPUs instead of AMD CPUs.
B. A suspended virtual machine cannot be migrated.
C. The hardware virtualization feature of the CPU is not enabled on the new hosts.
D. A vSphere Distributed Switch is required to migrate a suspended virtual machine.
【单选题】
A vSphere administrator has been using vSphere in evaluation mode and now wants to deploy an environment that provides the same features. Which edition of vSphere provides similar functionality to evaluation mode? ___
A. Enterprise Plus
B. Enterprise
C. Standard
D. Essentials
【单选题】
A vSphere administrator has been using vSphere in evaluation mode and now wants to deploy an environment that provides the same features. Which edition of vSphere provides similar functionality to evaluation mode? ___
A. Enterprise Plus
B. Enterprise
C. Standard
D. Essentials
【单选题】
An administrator has just configured the IP address on an ESXi host from the Direct Console User Interface. How can the configuration be validated as correct without any additional tools?___
A. Add the host to vCenter Server and if it works, then all networking settings are ok.
B. Select the Test Management Network option from the DCUI.
C. Connect to the host with the vSphere Client and click the Test Network option.
D. Use PowerCLI to connect to the host and initiate a network test.
【单选题】
An administrator is installing vCenter Server for an environment that has 40 ESXi 6.x Hosts and 150 virtual machines. Which database would meet the minimal requirements needed for this task? ___
A. vFabric Postgres
B. Microsoft SQL Express 2008
C. Microsoft SQL Server 2014
D. Oracle 11g
【单选题】
What is a requirement when enabling a Virtual SAN cluster in an existing High Availability (HA) and Distributed Resource Scheduler (DRS) Cluster? ___
A. Disable DRS and HA before enabling Virtual SAN
B. Enable DRS before enabling Virtual SAN
C. Disable HA before enabling Virtual SAN
D. Enable Storage DRS before enabling Virtual SAN
【单选题】
The vSphere administrator attempts to connect to an ESXi host via an SSH client and receives the following security alert: The vSphere administrator needs to determine whether the RSA key fingerprint shown in the security alert is the fingerprint of the intended ESXi host. Which tool should the vSphere administrator use? ___
A. Direct Console User Interface
B. vSphere Client
C. vSphere Web Client
D. vSphere Management Assistant
【单选题】
An administrator needs to monitor traffic on vSwitches in a vSphere 6.x environment. Which option, if configured, would accomplish this task? ___
A. Forged Transmits
B. MAC Address Changes
C. Promiscuous Mode
D. Notify Switches
【单选题】
What is true regarding datastores on ESXi 6.x? ___
A. NFS 4.1 datastore does not support Fault Tolerance (FT)
B. VMFS3 and VMFS5 datastores can be newly created
C. NFS datastore can be concurrently mounted using NFS 4.1 on one host and NFS on another
D. NFS 3.0 datastore does not support Fault Tolerance (FT)
【单选题】
An administrator is cloning and configuring five new web server virtual machines. What would be the benefit of configuring resource shares for the new VMs? ___
A. To prioritize access to a resource during contention.
B. To guarantee access to a resource during contention.
C. To prioritize access to a resource before contention occurs.
D. To guarantee access to a resource before contention occurs.
【单选题】
An administrator logs into the vSphere Web Client and sees the warning shown in the Exhibit. During a change control window, the warning was addressed. What should be done to verify that the host is no longer showing the warning? ___
A. Run a Remediate host operation.
B. Recheck the compliance of the host.
C. Restart the host to get rid of the warning.
D. Install VMware tools to clear the warning.
【单选题】
A vApp named Sales has a Memory Limit of 32 GB and a CPU Limit of 12,000 MHz. There are three virtual machines within the vApp: <Sales-DB -- Has a memory reservation of 20 GB. > <Sales-DC -- Has a memory reservation of 8 GB. > <Sales-Web -- Has a memory reservation of 8 GB.> Which statement is correct? ___
A. All three virtual machines can power on, but will have memory contention.
B. All three virtual machines can power on without memory contention.
C. Only two of the three virtual machines can power on.
D. Only one of the virtual machines can power on.
【单选题】
You are editing the management network configuration of an ESXi 6.x Host from the vSphere Web Client. You mistakenly put the incorrect VLAN in place for the management network. What action do you need to take to correct this? ___
A. You need to manually edit the configuration on the host with command line utilities.
B. No action is required. By default ESXi rolls back configuration changes that disconnect the host.
C. The ESXi host system configuration will need to be restored to the factory configuration to fix the issue.
D. The change can be reverted in the vSphere Web Client by simply editing the switch again.
【单选题】
What is true about resource pools created on a Distributed Resource Scheduler (DRS) cluster?___
A. A root resource pool is created with the specified values.
B. A root resource pool is automatically created using the aggregate total of the ESXi host resources in the cluster.
C. A root resource pool is automatically created using the aggregate total of all resources in the datacenter.
D. A root resource pool is not needed when creating resource pools on a DRS cluster.
【单选题】
An administrator attempts to enable Enhanced vMotion Compatibility (EVC) on a cluster. The operation results in a compatibility error, as shown in the exhibit. What is the likely cause of this error? ___
A. The CPUs in the ESXi host are not AMD CPUs.
B. The CPUs in the ESXi host do not support hardware virtualization capabilities.
C. The XD/NX CPU features have not been enabled in the BIOS of the server.
D. There is no shared storage between the hosts in the cluster.
【单选题】
What condition would prevent an administrator from creating a new VMFS3 datastore on an ESXi 6.x host using the vSphere Web Client? ___
A. A VMFS3 datastore cannot be created on an ESXi 6.x host.
B. The VMFS3 kernel module is not loaded.
C. A VMFS3 datastore cannot be mounted on an ESXi 6.x host.
D. VMFS3 datastores are not compatible with virtual machines created on an
E. SXi 6.x host.
【单选题】
During a new vSphere Distributed Switch configuration, where does the Maximum Transmission Unit (MTU) value get modified? ___
A. Uplink Settings
B. Switch Settings
C. Portgroup Settings
D. NIC Teaming Settings
【单选题】
A small company wants to use VMware products for its production systems. The system administrator needs to recommend a solution that will deliver High Availability to the company's production applications. What is minimum vSphere offering that will support this requirement? ___
A. vSphere Essentials
B. vSphere Essentials Plus
C. vSphere Hypervisor
D. vSphere Standard
【单选题】
Which scenario shows a reason for VMware Tools failing to install? ___
A. Virtual machine has a CD-ROM configured.
B. Guest OS Antivirus is blocking the VMware Tools installation.
C. Guest OS has 64-bit ldd (list dynamic dependencies) utility installed.
D. Virtual machine is powered on.
【单选题】
An administrator is configuring an ESXi 6.x host to use multiple NICs to resolve a management network redundancy error. After configuring a second NIC, the server is not able to communicate when the primary connection is taken down. The administrator analyzes the Exhibit shown here. Based on the exhibit, what is the likely cause of the issue? ___
A. vmnic4 is not attached to a vSwitch.
B. vmnic2 is not connected to a physical switch.
C. E1000 is the incorrect NIC
D. river for this card.
【单选题】
What information is required as part of an interactive ESXi 6.x installation? ___
A. Keyboard layout
B. IP Address
C. Root password
D. DNS information
【单选题】
What is the default load balancing policy for a newly created VMkernel port on a vSphere Distributed Switch? ___
A. Route based on orginating virtual port ID
B. Route based on IP Hash
C. Route based on source mac address
D. Route based on physical NIC load
【单选题】
An administrator deploys vCenter Server using the embedded Platform Services Controller. After testing the deployment for a couple of months, it is determined that the environment would be better served with an external Platform Services Controller. What should the administrator do to meet this new requirement? ___
A. Deploy a fresh instance of vCenter Server with an external Platform Services Controller.
B. Perform a fresh install of an external Platform Services Controller.
C. Migrate the embedded Platform Services Controller to an external Platform Services Controller.
D. Upgrade the embedded Platform Services Controller to an external Platform Services Controller.
【单选题】
Why are some virtual machines orphaned after rebooting a High Availability (HA) enabled host? ___
A. The Orphaned virtual machines have HA restart disabled.
B. The Orphaned virtual machines moved recently and the change did not persist.
C. The host is attached to failed storage.
D. The host just came out of maintenance mode.
【单选题】
Which vSphere 6 Standard Edition feature will allow an organization to ensure that critical multi-threaded applications have the maximum possible uptime? ___
A. Fault Tolerance
B. High Availability
C. Distributed Resource Scheduler
D. App HA
【多选题】
An application running in a virtual machine is experiencing performance issues. When utilizing performance monitoring utilities, it is noted that the CPU Utilization of the application is at 100%. Which two scenarios are probable causes of the CPU contention for the application? (Choose two.)___
A. There is a network I/O constraint.
B. There is a storage I/O constraint.
C. There is insufficient disk space assigned to the virtual machine.
D. The application is not virtualization aware.
【多选题】
A Fault Tolerance (FT) virtual machine with four vCPUs is experiencing high latency when performing ICMP and Application tests. What are three potential causes that may be attributing to this latency? (Choose three.)___
A. The FT network has insufficient bandwidth and is running on a 1GB Link.
B. The FT network is on a particularly high latency link.
C. The FT network has been configured with Network I/O Control.
D. The FT virtual machine is running an e1000 network adapter.
E. The
F. T virtual machine is running on poor performing network-based storage.
【多选题】
A virtual machine is experiencing performance issues. The following performance metrics are observed: <CPU usage value for the virtual machine is above 90%> < CPU ready value for the virtual machine is above 20%> Which two activities will likely resolve the performance issues? (Choose two.)___
A. Set a CPU reservation for the virtual machine.
B. Increase the CPU limit on the virtual machine.
C. Decrease CPU shares equally for all virtual machines on the host.
D. Increase CPU shares equally for all virtual machines on the host.
【多选题】
An administrator is upgrading a vSphere Distributed Switch. The existing switch is version 6.0 and the administrator wants to upgrade to the latest version possible. The environment contains several ESXi 6.1 hosts. Which two options are available to ensure that the upgraded switch will be compatible with these hosts? (Choose two.)___
A. Upgrade the vSphere Distributed Switch to 6.0
B. Upgrade the ESXi 5.5 hosts to version 6.0, then upgrade the vSphere Distributed Switch to 5.5
C. Upgrade the vSphere Distributed Switch to 5.1
D. Upgrade the
E. SXi host switches to 5.5, then upgrade the vSphere Distributed Switch to 5.5
【多选题】
An administrator attempts to create a Thick Provisioned Virtual Disk (VMDK) on an NFS datastore; but it fails. Which two reasons would explain the failure? (Choose two.)___
A. Datastore is on an NFS 3 storage server that does not support Hardware Acceleration
B. Datastore is on an NFS 4.1 storage server
C. Only VMFS datastores support "Thick Provisioned" VMDK
D. The NFS datastore was not created on a "Thick Provisioned" device
【多选题】
Which two NFS Protocol versions does vSphere 6 support? (Choose two.)___
A. Version 3
B. Version 3.1
C. Version 4
D. Version 4.1
【多选题】
Which three operations occur during a cold migration of a virtual machine? (Choose three.)___
A. The virtual machine disks are moved if the datastore is being changed.
B. The virtual machine is registered with the destination server.
C. The source virtual machine is removed from the old hosts.
D. The virtual machine hardware is upgraded.
E. The virtual machine files are quiesced prior to the migration.
【多选题】
A 4 GB Memory virtual machine is experiencing extended memory issues, as shown in the Exhibit. What potential issues could be attributed to this memory pressure?___
A. A limit is imposed on the virtual memory of this virtual machine.
B. The Balloon driver has been uninstalled.
C. A limit has been imposed on the Virtual CPU of the virtual machine.
D. Storage IO control has been enabled for the virtual machine causing the swapped memory.
【多选题】
You are creating a virtual machine in the Web Client using the New Virtual Machine wizard. Which two steps are required? (Choose two.)___
A. Select a valid name.
B. Select a cluster for the compute resource.
C. Select a network adapter.
D. Select the virtual machine compatibility.
【多选题】
An administrator has been given requirements to configure vMotion for a new virtual machine. The configuration should: <Provide Network Redundancy Use VLAN 550> <Be secured against anyone trying to spoof communication The vSwitch1 configuration is shown in the Exhibit.> Which three changes should be made to meet the stated requirements? (Choose three.)___
A. The VLAN ID must be set appropriately.
B. The default values for MAC Address Changes and Forged Transmits must be altered.
C. The teaming and failover adapters must be set appropriately.
D. The Traffic Shaping configuration must be altered.
E. The Load Balancing Policy must be set appropriately.
【多选题】
Which three traffic types are available services options when configuring a vmkernel port? (Choose three.)___
A. Provisioning Traffic
B. Virtual Volumes Traffic
C. vSphere Replication NFC Traffic
D. Virtual SAN Traffic
E. FCoE Traffic
【多选题】
An administrator logs into the vSphere Web Client, but is unable to see any hosts and clusters. Which two options could fix the problem? (Choose two.)___
A. Verify that the client web browser and vCenter Server are in the same broadcast domain.
B. Verify that the vCenter Server system is registered with the same Platform Services Controller as the vSphere Web Client.
C. Log in to the vCenter Server as a user within the Active
D. irectory domain.
【多选题】
Which three VLAN Tagging modes are available in vSphere 6.x? (Choose three.)___
A. External Switch Tagging
B. Private VLAN Tagging
C. Virtual Switch Tagging
D. VXLAN Tagging
E. Virtual Guest Tagging
【多选题】
Which two statements are true about VMFS5 datastores on ESXi 6.x? (Choose two.)___
A. Virtual Disk (VMDK) size can be larger than 2TB.
B. Datastore extent size can be larger than 2TB.
C. Only Physical Mode Raw
D. evice Map (Passthrough-RDM) can be larger than 2TB.
【多选题】
Which two statements are correct when turning off a Distributed Resource Scheduler (DRS) Cluster? (Choose two.)___
A. The resource pool hierarchy of the DRS cluster is maintained.
B. The resource pool hierarchy of the DRS cluster is removed.
C. The affinity settings of the
D. RS cluster are removed and not maintained when DRS is re-enabled.
