【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
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相关试题
【单选题】
能表示容性电路电压与电流关系的相量图是___。
【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。
【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___
【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___
【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。
【单选题】
7三端集成稳压器CW7812的输出电压是___。
【单选题】
8三端集成稳压器CXX7805的输出电压是___
【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。
【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___ 。
【单选题】
13三端集成稳压器 CW7906的输出电压是___
【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。
【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___
【单选题】
25三极管的反向电流ICBO是由___组成的。
A. 多数载流子
B. 少数载流子
C. 多数载流子和少数载流子
【单选题】
27如果在NPN型三极管放大电路中测得发射结为正向偏置，集电结也为正向偏置，则此管的工作状态为___
A. 放大状态；
B. 截止状态；
C. 饱和状态；
D. 不能确定。
【单选题】
28在以下三种电路中输入电阻最大的电路是___。
A. 共基放大电路
B. 共集放大电路
C. 共射放大电路
【单选题】
29在以下三种电路中既能放大电流，又能放大电压的电路是___。
A. 共基放大电路
B. 共集放大电路
C. 共射放大电路
【单选题】
30在以下三种电路中输出电阻最小的电路是___；
A. 共基放大电路
B. 共集放大电路
C. 共射放大电路
【单选题】
当PNP型晶体管工作在放大区时，各极电位关系为uC ___uB。
【单选题】
32当PNP型晶体管工作在放大区时，各极电位关系为uB___uE 。
【单选题】
33测得NPN型三极管上各电极对地电位分别为，，，说明此三极管处在___。
A. 放大区
B. 饱和区
C. 截止区
D. 反向击穿区
【单选题】
34若使三极管具有电流放大能力，必须满足的外部条件是___。
A. 发射结正偏、集电结正偏
B. 发射结反偏、集电结反偏
C. 发射结正偏、集电结反偏
D. 发射结反偏、集电结正偏
推荐试题
【单选题】
In a vSphere environment, two resource pools are created as shown in the Exhibit. Each VM is configured with 1 GB of memory. When the administrator tried to power on VM3, the operation failed. What action in the resource pool settings will allow VM3 to power on successfully?___
A. Deselect Expandable Memory Reservation
B. Increase Memory Reservation
C. Deselect Expandable CPU Reservation
D. Increase the CPU Reservation
【单选题】
Which network is used by vSphere HA when VMware vSAN is enabled?___
A. Management network
B. vSphere Replication network
C. vMotion network
D. VSAN network
【单选题】
Which statement is correct when migrating from a Windows vCenter Server to the vCenter Server Appliance 6.5?___
A. Migration deployments do not migrate local OS users from the source vCenter Server.
B. Migration deployments support DHCP on the source vCenter Server.
C. Migration deployments allow the source vCenter Server to remain powered on afterwards.
D. Migration deployments support custom ports for all services on the source vCenter Server.
【单选题】
How can failback of a recovered virtual machine in vSphere Replication be performed?___
A. No action required, because failback is automatically performed to the source site.
B. Configure a new replication in the reverse direction at the target site.
C. Disable or Stop the virtual machine replication on the source site.
D. Power off and unregister the virtual machine on the target site.
【单选题】
After upgrading the vSphere infrastructure and VMware Tools to version 6.5, the “Upgrade VM Compatibility” option is grayed out in the vSphere Web Client. (See Exhibit.) What must the administrator do to enable the VM compatibility upgrade?___
A. VMware Tools should be upgraded last.
B. Restart the ESXi server.
C. Uninstall VMware Tools.
D. Power off the virtual machine.
【单选题】
What availability mode does vCenter HA provide?___
A. Active-Passive
B. Active-Standby
C. Active-Active
D. Load-balanced
【单选题】
In which scenario will vSphere DRS balance resources when set to Fully Automated?___
A. Hosts with only shared storage
B. Hosts are part of a vSphere HA cluster
C. Power Management is set to Balanced on hosts
D. Hosts with shared or non-shared storage
【单选题】
What VMware technology can be used to move physical servers to the vSphere infrastructure?___
A. VMware vMotion
B. VMware Converter
C. VMware vCenter Server
D. OVF transport
【单选题】
Upgrading vCenter Server with Microsoft SQL database fails with the following error message: The DB User entered does not have the required permissions needed to install and configure vCenter Server with the selected DB. Please correct the following error(s): %sWhat could cause this error?___
A. incorrect ports open on SQL Server
B. incorrect database on the SQL server
C. incorrect compatibility mode on the SQL server
D. incorrect permission on SQL Server database
【单选题】
What is a potential downside of having more than four paths per datastore?___
A. limits the storage protocols
B. increases storage latency for VM
C. limits the path selection policies
D. limits the number of LUNs per host
【单选题】
Which feature facilitates the sharing of templates via vCenter Server?___
A. Content Library
B. OVF
C. folders
D. vApp
【单选题】
A vSphere Administrator is in the process of configuring replication for a virtual machine, but is not able to select the Recovery Point Objective (RPO) value of 5 minutes. Which statement could explain why the RPO value cannot be lower than 15 minutes?___
A. The OS quiescing option is selected for Replication options.
B. The virtual machine hardware version is not compatible.
C. The target and source sites use different types of datastores.
D. The target and source sites are not using VMFS 6.0 datastore.
【单选题】
What advanced parameter defines a custom isolation IP address for a vSphere HA cluster?___
A. das.usedefaultisolationaddress
B. das.isolationshutdowntimeout
C. fdm.isolationpolicydelaysec
D. das.isolationaddress
【单选题】
Which method is supported for backing up the virtual machine that contains vCenter Server?___
A. differential
B. incremental
C. full image
D. individual disks
【单选题】
A vSphere Administrator must ensure that a user is able to view and manage the system configuration in vSphere Web Client. In the vCenter Single Sign-On domain, which group should the user be a part of?___
A. SystemConfiguration.BashShellAdministrators
B. ComponentManager. Administrators
C. Administrators
D. SystemConfiguration.Administrators
【单选题】
What is the minimum number of hosts that must contribute capacity to a non-ROBO single site VMware vSAN cluster?___
【单选题】
Which guest operating system supports PVRDMA?___
A. Windows (32-Bit)
B. Linux (32-Bit)
C. Windows (64-Bit)
D. Linux (64-Bit)
【单选题】
What is the correct way to replace the certificate on an existing vCenter Server that is part of a vCenter HA configuration?___
A. Put the vCenter HA in Maintenance mode, replace the certificate, exit Maintenance mode.
B. Shut down Passive and Witness nodes and replace the certificate on the Active node.
C. Remove the Passive and Witness nodes, replace the certificate, reconfigure the cluster.
D. Replace the certificate while all nodes are participating in the cluster.
【单选题】
The vSphere Data Protection performance analysis results in the “Conditionally Passed” status. What can cause this condition?___
A. The results did not meet the minimum performance expectations.
B. The read, write, and seek tests were successful.
C. The read and write tests were successful but the seek test failed.
D. The read and write tests were successful but the seek test skipped.
【单选题】
A vSphere Administrator wants to reserve 0.5 Gbps for virtual machines on each uplink on a disturbed switch that has 10 uplinks. What is the quota that should be reserved for the network resource pool?___
A. 10 Gbps
B. 5 Gbps
C. 100 Gbps
D. 0.5 Gbps
【单选题】
A vSphere administrator manages a cluster which includes critical and non-critical virtual machines. The cluster requires different permissions for contractors and non-contractors. How can the administrator exclude the contractor group from some of the critical VMs?___
A. Apply permission for both contractors and non-contractors on the cluster level.
B. Apply permission for both contractors and non-contractors on the cluster level. Remove permission on the critical VMs for contractors.
C. Remove permission for contractors on the cluster level. Apply permission on the critical VMs for noncontractors.
D. Apply permission for both contractors and non-contractors on the VMs. Remove permission on the critical VMs for contractors.
【单选题】
In an ESXi 6.5 cluster only "NFS datastore has running or registered virtual machines" returns. A vSphere HA cluster with four hosts has admission control configured to tolerate one host failure. Which statement is true if a fifth host is added?___
A. CPU and Memory capacity will be set to 50%.
B. CPU and Memory capacity will be set to 30%.
C. CPU and Memory capacity will be set to 25%.
D. CPU and Memory capacity will be set to 20%.
【单选题】
Which command can be run to troubleshoot connectivity problems with vmkernal network interfaces?___
A. esxcli network
B. vmkping
C. net-status
D. vicfg-vmknic
【单选题】
What counter should an administrator check to determine if a virtual machine is ballooning?___
A. swapinRate
B. vmmemctltarget
C. swapped
D. vmmemctl
【单选题】
By default, how often is the vCenter vpx user password automatically changed?___
A. 15 days
B. 60 days
C. 30 days
D. 45 days
【单选题】
Which metric in the Exhibit would identify high latency for a virtual machine operating system?___
A. QAVG/cmd
B. KAVG/cmd
C. DAVG/cmd
D. GAVG/cmd
【单选题】
What VM Monitoring setting would ensure that the failure interval for a virtual machine is defined as 120 seconds?___
A. High
B. Normal
C. Low
D. Medium
【单选题】
The business managers have asked the IT administrator to ensure configuration compliance in the vSphere infrastructure. The IT administrator wants to use Host Profiles to accomplish this, but is unable to do so. Why is the administrator unable to use Host Profiles?___
A. The infrastructure uses a vSphere Standard license.
B. The infrastructure has servers with various CPU families.
C. The user has only the “Administrator” role.
D. Host Profiles apply only to storage settings.
【单选题】
What is the result of a “Consolidate” action on a virtual machine?___
A. All snapshots on the virtual machines will be deleted.
B. The virtual machine will be reverted to its last snapshot.
C. Redundant delta disks will be combined and deleted.
D. A new snapshot with memory state will be created.
【单选题】
A Telco customer is implementing NFV using vSphere as the virtualization platform. Which feature can help achieve a high packet rate with lower CPU consumption?___
A. Network I/O Control
B. SplitRX
C. ERSPAN
D. LACP
【单选题】
What is the VMware-recommended best practice for Fibre Channel zoning?___
A. soft zoning
B. single-initiator-multiple-target zoning
C. single-initiator zoning
D. single-initiator-single-target zoning
【单选题】
How can a vSphere administrator ensure that a set of virtual machines run on different hosts in a DRS cluster?___
A. Use a VM-Host affinity rule.
B. Add the VMs to a vApp.
C. Use a VM-VM affinity rule.
D. Place the VMs in different folders.
【单选题】
vCenter Server Appliance Instance can be backed up using which Client Interface?___
A. vSphere Client Interface
B. vSphere Web Client Interface
C. VMware Host Client Interface
D. Virtual Appliance Management Interface
【单选题】
What tool can capture network traffic at the uplinks, or vSwitch, or virtual port levels?___
A. tcpdump-uw
B. wireshark
C. pktcap-uw
D. pcap
【单选题】
Which storage feature always requires the use of third-party software on ESXi?___
A. Hardware Acceleration for NAS devices
B. VVOL
C. Hardware Acceleration for Block
D. evices
【单选题】
An ESXi host's VMCA-Signed certificate has expired. How can the certificate be renewed?___
A. In the vSphere Web Client, browse to the host in question. Click the Manage tab and select settings. Select System and click Certificate, then click the Renew button.
B. In the vSphere Web Client, browse to the host in question. Click the Manage tab and select settings. Select System and click Certificate, then click the Refresh CA Certificates button.
C. Run the command /sbin/generate-certificates on the affected host.
D. Disconnect the host from vCenter Server and reconnect it.
【单选题】
Which is the correct order for upgrading vSphere components?___
A. vCenter Server, ESXi hosts, VMware Tools, Virtual Machine hardware
B. VMware Tools, Virtual Machine hardware, ESXi hosts, vCenter Server
C. vCenter Server, Virtual Machine hardware, VMware tools, ESXi hosts
D. ESXi hosts, vCenter Server, Virtual Machine hardware, VMware Tools
【单选题】
Which iSCSI initiator type can be used with any network interface card?___
A. Software iSCSI initiator
B. Software FCoE adapter
C. Hardware Independent iSCSI initiator
D. Hardware Dependent iSCSI initiator
【单选题】
An administrator is attempting to power on a virtual machine with 32GB of memory. The operation fails with the following error: <Could not power on VM: No space left on device> <Checking the space on the virtual machine's datastore, there is 30GB free.> Which action would allow the VM to power on?___
A. Set a 2GB memory reservation on the VM.
B. Mount the virtual disk from the affected VM on to another virtual machine and free up space from within the OS.
C. Enable vSphere HD admission control on the cluster in which the VM resides.
D. Set a 2GB memory limit on the VM.
【单选题】
An administrator attempts to manually reclaim space on thin-provisioned VMFS6 volumes but finds that no additional space is being recovered. Which could be causing this?___
A. vSphere 6.5 does not support manual UNMAP.
B. The manual UNMAP operation has been moved to the vSphere web client.
C. The VASA version is use is incompatible.
D. UNMAP is automated for VMFS6.
