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【单选题】
电感两端的电压相位超前电流___。
A. 90°
B. 180°
C. 360°
D. 30°
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相关试题
【单选题】
电容两端的电压相位滞后电流___。
A. 30°
B. 90°
C. 180°
D. 360°
【单选题】
应用戴维南定理求含源二端网络的输入等效电阻是将网络内各电动势___
A. 串联
B. 并联
C. 短接
D. 开路
【单选题】
LC 选频振荡电路,当电路频率等于谐振频率时,电路性质为___。
A. 电阻性
B. 感性
C. 容性
D. 纯电容性
【单选题】
阻值为4Ω的电阻和容抗为3Ω的电容串联,总复数阻抗为___
A. 3+j4
B. 3-j4
C. 4+j3
D. 4-j3
【单选题】
电动势为10V,内阻为2Ω的电压源变换成电流源时,电流源的电流和内阻是___
A. 10A,2Ω
B. 20A,2Ω
C. 5A,2Ω
D. 2A,5Ω
【单选题】
电流为5A,内阻为2Ω的电流源变换成一个电压源时,电压源的电动势和内阻为___
A. 10V,2Ω
B. 2.5V,2Ω
C. 0.4V,2Ω
D. 4V,2Ω
【单选题】
额定电压都为220V的40W、60W、100W三灯泡串联在220V的电源中,它们的发热量由大到小排列为___
A. 100W 60W 40W
B. 40W 60W 100W
C. 100W 40W 60W
D. 60W 100W 40W
【单选题】
在正弦交流电的解析式i=ImSin(ωt +φ)中,φ表示___
A. 频率
B. 相位
C. 初相位
D. 相位差
【单选题】
正弦交流电压u=100Sin(628t + 600)V,它的最大值为___。
A. 100 V
B. 100 V
C. 60V
D. 628 V
【单选题】
能表示容性电路电压与电流关系的相量图是___。
A.
B.
C.
D.
【单选题】
如图判断同名端为___
A. a与c
B. a与 d
C. b与c
【单选题】
电路中___定律指出:流入任意一节点的电流必定等于流出该节点的电流。
A. 欧姆
B. 基尔霍夫电流
C. 楞次
D. 基尔霍夫电压
【单选题】
已知电源电压为12 V ,四只相同灯泡的工作电压都是6 V,要使灯泡都能正常工作,则灯泡应___
A. 全部串联
B. 两只并联后与另两只串联
C. 两两串联后再并联
D. 全部并联
【单选题】
用戴维南定理分析电路“入端电阻”时,应将内部的电流源___处理。
A. 作开路
B. 作短路
C. 不进行
【单选题】
任何一个含源二端网络都可以用一个适当的理想电压源与一电阻___来代替。
A. 串联
B. 并联
C. 串联或并联
D. 随意联接
【单选题】
用交流电流表测得交流电流10A,则电路中电流的最大值为___。
A. 10A
B. 14.1A
C. 20A
D. 70.7A
【单选题】
如右图所示电路中,已知各支路的电流I1=I2=10A, 则电路的总电流I为___。
A. 20A
B. 0 A
C. 14.1A
D. 50A
【单选题】
1杂质半导体中多数载流子的浓度取决于___
A. 温度
B. 杂质浓度
C. 电子空穴对数目
【单选题】
2在电场作用下,空穴与自由电子运动形成的电流方向___
A. 相同
B. 相反
【单选题】
3光敏二极管应在___下工作
A. 正向电压
B. 反向电压
【单选题】
4下列半导体材料哪一种的热敏性突出“导电性受温度影响最大”?___
A. 本征半导体
B. N型半导体质
C. P型半导体
【单选题】
5用万用表电阻挡检测某一个二极管时,发现其正、反电阻均近于1000KΩ,这说明该二极管是属于___。
A. 短路状态;
B. 完好状态;
C. 断路状态;
D. 极性搞错。
【单选题】
6稳压二极管是一个可逆击穿二极管,稳压时工作在___状态。
A. 正偏
B. 反偏 E、正向导通 F、截止
【单选题】
7三端集成稳压器CW7812的输出电压是___。
A. 12V
B. 5V
C. 9V
【单选题】
8三端集成稳压器CXX7805的输出电压是___
A. 5v
B. 9v
C. 12v
【单选题】
9一个平衡PN结,用导线将P区和N区连起来,而导线中___。
A. 有微弱电流
B. 无电流
C. 有瞬间微弱电流
【单选题】
10二极管两端正向电压大于___电压时,二极管才导通。
A. 击穿电压;
B. 死区;
C. 饱和。
【单选题】
11当温度升高时,二极管的反向饱和电流 ___ 。
A. 增大;
B. 减小;
C. 不变;
D. 无法判定。
【单选题】
12硅二极管的正向导通压降比锗二极管的___ 。
A. 大
B. 小
C. 相等
【单选题】
13三端集成稳压器 CW7906的输出电压是___
A. -12v
B. -9v
C. -6V
【单选题】
14稳压管的工作是利用伏安特性中的___。
A. 正向特性
B. 反向特性
C. 反向击穿特性
【单选题】
15二极管具有___
A. 正向特性
B. 反向特性
C. 单向导电特性
D. 反向击穿特性
【单选题】
16图中D1-D3为理想二极管,A,B,C灯都相同,试问___灯最亮。
A. A灯
B. B灯
C. C灯
【单选题】
18在单相桥式整流电容滤波电路中,设U2为其输入电压,输出电压的平均值约为___。
A. U0=0.45U2
B. U0=1.2U2
C. U0=0.9U2
D. U0=1.4U2
【单选题】
19在单相桥式整流电路中,设U2为其输入电压,输出电压的平均值约为___。
A. U0=0.45U2
B. U0=1.2U2
C. U0=0.9U2
D. U0=1.4U2
【单选题】
20在半波整流电容滤波电路中,设U2为其输入电压,输出电压的平均值约为___。
A. U0=0.45U2
B. U0=1.2U2
C. U0=0.9U2
D. U0=1.4U2
【单选题】
21在半波整流电路中,设U2为其输入电压,输出电压的平均值约为___。
A. U0=0.45U2
B. U0=1.2U2
C. U0=0.9U2
D. U0=1.4U2
【单选题】
22温度影响了放大电路中的___,从而使静态工作点不稳定。
A. 电阻;
B. 电容;
C. 三极管;
D. 电源。
【单选题】
23用直流电压表测得放大电路中某三极管各极电位分别是2V、6V、2.7V,则三个电极分别是___。
A. [B、C、E]
B. [C、B、E]
C. [E、C、B]
【单选题】
24共射极放大电路的交流输出波形上半周失真时为___
A. 饱和失真
B. 截止失真
C. 交越失真
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【多选题】
Which two are true about the Risk badge in vRealize Operations? (Choose two.)___
A. The Risk badge indicates potential future problems that may degrade the performance of the system.
B. Risks may require attention in the near future.
C. The Risk badge indicates problems that are degrading performance of the system.
D. Risks require attention now to correct system performance problems.
【多选题】
vSphere Update Manager allows which two virtual machine attributes to be upgraded? (Choose two.)___
A. Virtual machine firewall policies for NSX.
B. Software Packages in the virtual machine.
C. Virtual machine Hardware Version.
D. VMware Tools Upgrade.
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What are two benefits of using NFS 4.1 with vSphere 6.x as compared to NFS 3? (Choose two.)___
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B. NFS 4.1 supports multipathing
C. NFS 4.1 supports IPv6
D. NFS 4.1 supports hardware acceleration
【多选题】
Which three statements are true regarding Fault Tolerance? (Choose three.)___
A. Applications need to be continuously available to users.
B. Applications without native clustering capabilities can be protected.
C. Custom clustering solutions are complicated to configure and maintain.
D. Applications that have 16 vCPUs are supported.
E. Prevents application crashes by analyzing the workload and correcting problems.
【多选题】
Which two statements are true regarding VMware vSphere Flash Read Cache (vFRC)? (Choose two.)___
A. Cache fills and cache evictions happen in the granularity of a cache block size.
B. vFRC caches data from both read and write I/Os, but write I/Os are always serviced by the underlying storage.
C. vFRC caches data from both read and write I/Os, but write I/Os are always serviced by the underlying cache data.
D. Cache fills and cache evictions happen in the granularity of the disk block size.
【多选题】
What are two possible causes of Storage Distributed Resource Scheduler (SDRS) being disabled on one or more virtual machine disks in a datastore cluster? (Choose two.)___
A. The virtual machine has vSphere Fault Tolerance disabled.
B. The virtual machine is a template.
C. The virtual machine swap file is on a shared datastore.
D. The disk is a CD-ROM/ISO file.
【多选题】
An administrator attempts to install vCenter Single Sign-On Server. The installer returns an error message indicating that the installation failed. Prior to the installation, all setup prerequisites were met. The administrator has generated a vCenter Server Single Sign-On support bundle. Which two files should the administrator analyze to determine the cause of the failure? (Choose two.)___
A. Server\utils\logs\imsTrace.log
B. Server\utils\logs\install.txt
C. %TEMP%\utils\logs\vminst.log
D. %TEMP%\vminst.log
【多选题】
An administrator is unable to remove an ESXi 6.x host from a vSphere Distributed Switch. What are two likely reasons for this issue? (Choose two.)___
A. Vmkernel interfaces on the switch are still in use.
B. VM Network port group adapters are connected to different switch.
C. Physical NICs are migrated to different switch.
D. VM Network adapters are connected to this switch.
【多选题】
Which two Identity Sources are available to add for vCenter Single Sign-On authentication? (Choose two.)___
A. LocalOS
B. OpenLDAP
C. NIS as an LDAP Server
D. VCMSDS
【多选题】
What are three goals of resource management within a cluster? (Choose three.)___
A. To prevent virtual machines from monopolizing resources and to guarantee predictable service rates.
B. To exploit undercommitted resources and overcommit with graceful degradation.
C. To provide solutions to potential problems that you might encounter when using vCenter Server.
D. To control the relative importance of virtual machines and provide flexible dynamic partitioning.
E. To provide additional network administration capabilities.
【多选题】
Which three actions can be taken as a result of executing the vSphere Update Manager 6.x scan and remediation wizards? (Choose three.)___
A. Install and upgrade software in virtual machines.
B. Upgrade the firmware on ESXi host devices.
C. Upgrade and Patch ESXi hosts.
D. Install and update third-party software on hosts.
E. Upgrade virtual machine hardware.
【多选题】
Which two statements are true about deploying and using vSphere Replication? (Choose two.)___
A. ESXi hosts managed by a single vCenter Server instance require a connection between the two vSphere Replication appliances.
B. Sites managed by different vCenter Server instances require a connection between the two vSphere Replication appliances.
C. Sites managed by different vCenter Server instances require the use of Site Recovery Manager and a connection between the two vSphere Replication appliances.
D. ESXi hosts managed by a single vCenter Server instance require a single vSphere Replication appliance.
【多选题】
An administrator is attempting to power on a virtual machine, but the task is hanging at 95%. What three scenarios best explain why this problem is happening? (Choose three.)___
A. A virtual machine question is currently being posed to the administrator.
B. Another task for the virtual machine or other component is already in progress.
C. The VMware High Availability cluster has insufficient resources to guarantee failover.
D. The host has lost access to the storage device containing the virtual machine files.
E. The host is under resource contention and unable to power on the virtual machine.
【多选题】
Which three features are not supported when using Fault Tolerance in vSphere 6.x? (Choose three.)___
A. Virtual Volumes (VVOLS)
B. Storage vMotion
C. Virtual Machine Component Protection
D. vMotion
E. vSphere Distributed Switches
【多选题】
Which two storage controller configurations can be used with Virtual SAN? (Choose two.)___
A. SAS controllers in Passthrough mode
B. SAS controllers in RAID0 mode
C. SAS controllers in RAID1 mode
D. SAS controllers in RAID10 mode
【多选题】
Which three are requirements when using vMotion to move a virtual machine across vCenter Server systems? (Choose three.)___
A. Both vCenter Servers must be using Enhanced Linked Mode.
B. Both vCenter Servers must be in the same Single Sign-On Domain.
C. Time must be synchronized.
D. Duplicate VM MAC addresses must be configured.
E. Both vCenter Servers must have High Availability enabled on source and destination clusters.
【多选题】
Which two components can be used when configuring Enhanced Linked Mode? (Choose two.)___
A. vCenter Server Appliance
B. vRealize Operations Manager
C. vSphere Management Appliance
D. vCenter Server for Windows
【多选题】
An organization has a number of virtual machines that would benefit from Fault Tolerance. These include: <A single vCPU Apache Server> < A dual vCPU vCenter Server> < A quad vCPU SQL Server> <An eight vCPU Hadoop Server>. Which two virtual machines can be configured to use VMware Fault Tolerance? (Choose two.)___
A. Apache Server
B. vCenter Server
C. SQL Server
D. Hadoop Server
【多选题】
Which two badges are major badges in vRealize Operations? (Choose two.)___
A. Risk
B. Efficency
C. Workload
D. Faults
【多选题】
An administrator is deploying multiple Windows 2003 Virtual Machines from the same template. What two steps should be taken to avoid network conflicts? (Choose two.)___
A. Customize the guest operating system.
B. Install VMware Tools into the new virtual machines.
C. Copy the Microsoft Sysprep tools onto the vCenter Server system.
D. Ensure the e1000 vmnic is selected for each new virtual machine.
【多选题】
Which three conditions would prevent Storage I/O Control from being enabled on a group of datastores? (Choose three.)___
A. The datastores planned for the solution are used by different vSphere clusters.
B. A datastore planned for the solution is configured as a Raw Device Mapping file.
C. A datastore planned for the solution has three extents.
D. A datastore planned for the solution is configured as NFS.
E. The organization has an Enterprise license.
【多选题】
Which two actions are prerequisites to adding ESXi 6.x hosts to a vSphere Distributed Switch? (Choose two.)___
A. Verify that there is at least one Distributed Port Group on the Distributed Switch.
B. Verify that the Distributed Port Group have active uplinks configured in its teaming and failover policy.
C. Verify that the
D. istributed Switch has been configured with a Network Profile.
【多选题】
An organization has configured Distributed Power Management (DPM) on a vSphere 6 cluster. The organization wants to be alerted when an ESXi host has been powered down by DPM. Which two options represent the type and name of the alarm that would accomplish this? (Choose two.)___
A. DrsEnteringStandbyModeEvent
B. DrsEnteredStandbyModeEvent
C. Event-based
D. Condition-based
【多选题】
Which two allow for the disabling of Network Rollback operations? (Choose two.)___
A. Modifying the vpxd advanded configuration options and adding the config.vpxd.network.rollback key
B. Modifying the C:\ProgramData\VMware\CIS\cfg\vmware-vpx\vpxd.cfg file and adjusting the<rollback> xml tag
C. Modifying the C:\ProgramData\VMware\CIS\cfg\vmware-vpx\vpxd.cfg file and adjusting the <networkrollback> xml tag
D. Modifying the C:\ProgramData\VMware\CIS\cfg\vmware-vpx\firstboot\vpxd-service- spec.prop file and adjusting the <rollback> xml tag
【多选题】
An administrator is tasked with performing a vMotion migration of a virtual machine. The virtual machine is configured as follows: <vSphere Flash Read Cache (vFRC) enabled> <Is part of a Distributed Resource Cluster (DRS) Cluster> Which two statements are true? (Choose two.)___
A. Each ESXi host in the cluster supports multiple virtual flash resources.
B. Each ESXi host in the cluster supports one virtual flash resource.
C. DRS treats powered-on virtual machines with Flash Read Cache as having a preferred affinity to their current host and moves them only for mandatory reasons.
D. DRS treats powered-on virtual machines with Flash Read Cache as having a required affinity to their current host and does not move them.
【多选题】
An administrator is using the Host Failures to Tolerate Admission Control Policy for a vSphere High Availability ___ cluster. When configuring this setting on the cluster, the administrator sees this error message: <Insufficient resources to satisfy HA failover level on cluster > What are two likely causes for the error? (Choose two.)(AB)
A. The hosts in the cluster are disconnected.
B. A host in the cluster is displaying an HA error.
C.
D. istributed Resource Scheduler has not been configured on the cluster.
【多选题】
What are two ways to identify TCP/IP stack information? (Choose two.)___
A. Using the vSphere Web Client
B. Using esxcli network ip netstack
C. Using esxcfg-netstack
D. Using the vSphere Client
【多选题】
Which two actions are required when enabling vFlash Read Cache for a virtual machine's virtual disk? (Choose two.)___
A. A value in the Virtual Flash Read Cache text box must be entered.
B. A Flash Resource Pool for Cache size reservation must be entered.
C. The Device backing and the block size must be configured.
D. The
E. nable virtual flash host swap cache check box must be selected.
【多选题】
What two IT infrastructure components are virtualized by vSphere Essentials? (Choose two.)___
A. Networks
B. Applications
C. Storage
D. Management
【多选题】
When attempting to access a virtual machine, an administrator is unable to login using the vSphere credentials. What two options are probable causes of the authentication failure? (Choose two.)___
A. The vSphere credentials have not been granted permissions.
B. The vSphere credentials are granted read-only permissions.
C. The vSphere credentials are granted no-access permissions.
D. The vSphere credentials are not a member of the local administrator group.
【多选题】
An administrator is performing a scripted installation of ESXi 6.x. In which three locations does the script need to be? (Choose three.)___
A. PXE Server
B. HTTPS
C. FTP
D. NFS
E. VVOLs Datastore
【多选题】
In order for a company to meet regulatory requirements, all ESXi 6.x Hosts must be configured to direct logs to a syslog server. What are two ways ESXi hosts can configured for this action? (Choose two)___
A. Use the esxcli system syslog command.
B. Edit them in the ESXi host Advanced System Settings.
C. From the Syslog collector user interface of the Web Client.
D. Syslog logging is not available for
E. SXi Hosts.
【多选题】
Which three actions can be executed when an alarm is triggered? (Choose three.)___
A. Send an email.
B. Send an SNMP trap.
C. Run a script or command.
D. Run an Orchestrator workflow.
E. Send a trigger to syslog.
【多选题】
An administrator is attempting to power on a virtual machine, but is unable to do so. Which two reasons are probable causes of the failure? (Choose two.)___
A. Storage access to the virtual machine swap file has been lost.
B. One of the virtual machine VMDK files is locked.
C. Virtual machine is running CentOS 7.0 64-bit.
D. Virtual machine has Hyper-Threading enabled.
【多选题】
An administrator has configured a host profile so that ESXi 6.x hosts will point to the corporate NTP server for time synchronization. The NTP server is located at 10.0.30.213, but time has not been synchronized properly across the ESXi hosts. The administrator reviews Host Profile settings as shown in the Exhibit. Which two steps are required to resolve the issue? (Choose two.)___
A. Correct the NTP server IP address.
B. Check the host for host profile compliance.
C. Remediate the host based on the updated host profile.
D. Change the NTP server to the FQDN as IP Addresses are not supported.
【多选题】
An administrator is attempting to migrate a large Hadoop virtual machine using vMotion. The administrator notices a delay when the machine is quiesced. The Hadoop virtual machine is processing many transactions a second to an in-memory database. Which two actions would help reduce the amount of time needed to perform a vMotion on this virtual machine? (Choose two.)___
A. Use multiple NICs for the vMotion vmkernel port.
B. Use a 10Gbps Network card for the vMotion vmkernel port.
C. Add an additional management network to help transmit the data quicker.
D. Disable Fault Tolerance before performing the vMotion.
【多选题】
An administrator is installing a new network card in an ESXi 6.x host that is part of a vSphere cluster. When the host is placed into maintenance mode, the vSphere Web Client displays the progress bar at 2% for over 30 minutes. Which two are likely reasons for this occurrence? (Choose two.)___
A. Maintenance mode is unable to migrate all virtual machines from the host.
B. There is a large number of virtual machines that must be migrated from the host.
C. VMware High Availability is in the process of reconfiguring the cluster.
D. Each virtual machine on the
E. SXi host must be reconfigured to recognize the new adapter.
【多选题】
Which two events happen when Distributed Resource Scheduler (DRS) is disabled? (Choose two.)___
A. The cluster's resource pool heirarchy and affinity rules are re-established when DRS is turned back on.
B. The cluster's resource pool hierarchy and affinity rules are not re-established when DRS is turned back on.
C. The cluster's resource pools are removed from the cluster.
D. The cluster's resource pools are removed from the cluster and assigned to the hosts.
【多选题】
Which two networking connection types can be configured on a virtual switch? (Choose two.)___
A. Virtual machine portgroups
B. VMkernel services (such as NFS, iSCSI, or vMotion) to the physical network
C. Web services over the Management Network
D. NFS and FCoE storage services
【多选题】
An administrator creates a DRS cluster of eight ESXi 6.x hosts. There are 10 virtual machines balanced across the hosts. An attempt to place the first host into maintenance mode fails. What are two reasons that the host failed to enter maintenance mode? (Choose two.)___
A. The DRS cluster Automation Level is set to Partially Automated mode.
B. One of the virtual machines on the ESXi Host entering maintenance mode is configured with a DRS Host affinity rule Should run on hosts in group.
C. One of the virtual machines on the ESXi Host entering maintenance mode is configured with a DRS Host affinity rule Must run on hosts in group.
D. One of the virtual machines on the
E. SXi Host entering maintenance mode is configured with an individual Automation Level set to Partially Automated.
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