相关试题
【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
【单选题】
35在由PNP晶体管组成的基本共射放大电路中，当输入信号为1KHz、5mV的正弦电压时，输出电压波形出现了顶部削平的失真。这种失真是___ 。
A. 饱和失真
B. 截止失真
C. 交越失真
D. 频率失真
【单选题】
36在由PNP晶体管组成的基本共射放大电路中，当输入信号为1KHz、5mV的正弦电压时，输出电压波形出现了底部削平的失真。这种失真是___ 。
A. 饱和失真
B. 截止失真
C. 交越失真
D. 频率失真
【单选题】
37共集电极放大电路中Re的负反馈组态是___。
A. 电压串联负反馈
B. 电流串联负反馈
C. 电压并联负反馈
【单选题】
38为了使放大器带负载能力强，一般引入___负反馈。
【单选题】
41为了提高三极管放大电路的输入电阻，采用___负反馈 i=i1+i2
【单选题】
42为了稳定输出电流，采用___负反馈。
【单选题】
43为了改善放大器的动态性能，应该引入___电路。
A. 直流负反馈
B. 交流负反馈
C. 电压负反馈
D. 电流负反馈
【单选题】
44为了稳定放大器的静态工作点，应该引入___电路。
A. 直流负反馈
B. 交流负反馈
C. 电压负反馈
D. 电流负反馈
【单选题】
45共模抑制比是差分放大电路的一个主要技术指标，它反映放大电路___能力。
A. 放大差模抑制共模
B. 输入电阻高
C. 输出电阻低
【单选题】
46差分放大电路是为了___而设置的。
A. 稳定Au
B. 放大信号
C. 抑制零点漂移
【单选题】
47分析运放的“虚短”是指是___。
A. U-≈U+
B. I-≈I+≈0
C. U0=Ui
D. U-≈U+≈0
推荐试题
【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.
【单选题】
An administrator has upgraded to vSphere 6.5 and also wants to use Kerberos authentication for NFS. Which can be done to the existing NFSv3 volumes to enable this feature?___
A. Perform a storage rescan on VMFS volumes.
B. Unmount the NFSv3 datastore, and then mount as NFSv4.1 datastore.
C. Nothing. All NFSv3 mounted datastores are upgraded automatically during vSphere upgrades.
D. Perform a scan of new storage devices.
【单选题】
An administrator wants to restore the vCenter Server Appliance 6.5 from backup. Where can this be accomplished?___
A. from the ESXi Host Client
B. from the VMware vSphere Appliance Management Interface
C. from within the VMware vSphere Web Client
D. from the vCenter Server Appliance Installer
【单选题】
The administrator wants to power on VM-K2, which has a 2GHz CPU reservation. VM-M1, VM-M2, and VM-K1 are all powered on. VM-K2 is not powered on. The exhibit shows the parent and child resource reservations. If Resource Pool RP-KID is configured with an expandable reservation, which statement is true?___
A. VM-K2 will be unable to power on because there are insufficient resources.
B. VM-K2 will be able to power on since resource pool RP-KID has 2GHz available.
C. VM-K2 will be unable to power on because only 2GHz are reserved for RP-KID.
D. VM-K2 will receive resource priority and will be able to power on this scenario.
【单选题】
Which is the block size on the VMFS6 datastore?___
A. All small and large file blocks are 8MB.
B. All small and large file blocks are 1MB.
C. Small file blocks are 512KB. large file blocks are 64MB.
D. Small file blocks are 1MB, large file blocks are 512MB.
【单选题】
When installing vCenter Converter Standalone, why must an administrator perform a client-server installation instead of a local installation?___
A. to manage conversion tasks remotely
B. to convert virtual machines as well as physical machines
C. to allow installation of the Converter agent on remote source machines
D. to hot clone physical or virtual machines
【单选题】
Which is required by vCenter Converter Standalone to convert a physical Red Hat Enterprise Linux 7 machine to a virtual machine?___
A. The Linux machine must be powered off.
B. The Linux machine must have the SSH daemon started.
C. The Linux machine must use a static IP address.
D. The Linux machine must have a fully-qualified domain name.
【单选题】
An administrator is troubleshooting network communications between a vCenter Server and an ESXi 6.5 host. Which log shows the related events between these components?___
A. /var/log/fdm.log
B. /var/log/vpxa.log
C. /var/log/hostd.log
D. /var/log/auth.log
【单选题】
An administrator has recently upgraded from vSphere 6.0 to 6.5, and can no longer see the software iSCSI named vmhba33. Which could be the reason for this?___
A. The upgrade has changed the vmhba name.
B. vSphere 6.5 automates iSCSI configurations.
C. vSphere 6.5 no longer supports software iSCSI.
D. The upgrade has deleted the vmhba.
【单选题】
An administrator is trying to vMotion a VM from his datacenter to a recovery site. Which is the maximum allowed RTT (Round-Trip Time) latency between source and destination host?___
A. 100 milliseconds
B. 150 milliseconds
C. 15 milliseconds
D. 10 milliseconds
【单选题】
Which is required for configuring iSCSI Software Adapter network port binding?___
A. VMkernel of the iSCSI traffic must be load balanced using Route based on IP Hash algorithm.
B. VMkernel of the iSCSI traffic must be load balanced using Route based on Source Virtual Port ID algorithm.
C. VMkernel of the iSCSI traffic must be load balanced using Route based on Source MAC Hash algorithm.
D. VMkernel of the iSCSI traffic must be bound to only one active network adapter.
【单选题】
In vSphere Data Protection 6.1, which is the function of a Backup Verification job?___
A. None. Backup Verification job is not a feature of vSphere Data Protection
B. It is a manual task -Power it on -Verify the guest OS -Check started applications
C. It is an automatic process -Restore a virtual machine -Power it on -Verify that the guest OS is booted by communicating with the Backup Verification agent
D. It is an automatic process -Restore a virtual machine -Power it on -Verify that the guest OC is booted by detecting the VMware ToolsTM "heartbeats"
【单选题】
An administrator has enabled vSphere Distributed Switch Health Check. The hosts connected to that Distributed Switch all display an alert:< vSphere Distributed Switch MTU supported status > .The administrator has all of the VMkernel ports MTU sizes set to 1600. Which action will remedy this problem?___
A. Configure the Distributed Switch to MTU 9100.
B. Disconnect and reconnect the physical network cable.
C. Configure the physical switch to MTU 1600.
D. Disable the Distributed Switch MTU.
【单选题】
Which Host Profile Subprofile configuration is used to configure firewall settings for ESXi hosts?___
A. Advanced Configuration Settings
B. General System Settings
C. Security
D. Networking
【单选题】
Where would a vSphere administrator find general vCenter Server logs on a vCenter Server Appliance?___
A. /var/log/vmware/vpxd/
B. /var/log/messages
C. /etc/vmware-vpx/
D. /var/log/vmware/vsan-health/
【单选题】
An administrator wishes to enable network port mirroring based on source port. Which feature should be enabled?___
A. vSphere standard switch port
B. ERSPAN
C. NSX Virtual Wire
D. VLAN
【单选题】
Which CLI command shows the physical uplink status for a vmnic?___
A. esxcli network ip connection list
B. esxcli network ip neighbor list
C. esxcli network nic get
D. esxcli network nic list
【单选题】
Which is the maximum number of block devices (LUNs) that are supported by ESXi hosts that are running version 6.5?___
A. 1024
B. 512
C. 2048
D. 256
【单选题】
When performing a vCenter Server 5.5 for Windows with Microsoft SQL Server Express database migration to vCenter Server Appliance 6.5, which will be the target database?___
A. Microsoft SQL Server Express 2012R2
B. Microsoft SQL Server Standard 2012R2
C. PostgreSQL
D. Oracle DB 11g
【单选题】
An administrator has multiple vCenter Server 6.5 systems but cannot enable Storage I/O Control (SIOC) on a datastore shared by ESXi hosts managed by the vCenter Server systems. Which action should the administrator take to resolve the issue?___
A. Unmount the datastore and then enable SIOC on the vCenter Server system.
B. Configure the datastore to be managed by a single vCenter Server system.
C. Configure Storage DRS and then enable SIOC on the vCenter Server system.
D. Enable Raw Device Mapping (RDM) on the
E. SXi hosts.
【单选题】
“OneAppServer” is a VM template stored in a content library named “LibraryOne”, but the vSphere administrator is not able to use this template for deployment. Why is the administrator unable to deploy OneAppServer?___
A. OneAppServer must be updated before it can be deployed.
B. LibraryOne is a subscribed library and OneAppServer is not downloaded yet.
C. LibraryOne is published and optimized for syncing over HTTP.
D. OneAppServer was imported from a local file on the system.
【单选题】
An administrator sets the Failover Capacity for both CPU and Memory at 25%. Based on the Exhibit below, how much of the cluster’s total CPU resources are still available to power on additional virtual machines?___
A. 45%
B. 25%
C. 70%
D. 60%
【单选题】
Which statement applies to the vSphere Replication appliance?___
A. Only one vSphere Replication appliance can be deployed per vCenter Server instance.
B. VMware Tools in the vSphere Replication appliance can be upgraded.
C. A single vSphere Replication appliance can manage a maximum of 4000 replications.
D. vSphere Replication is available only with the vSphere
E. ssentials Plus license.
【单选题】
Which esxcli namespace can a vSphere Administrator use to adjust the queue depth?___
A. esxcli system module parameters
B. esxcli storage core device
C. esxcli system module set
D. esxcli storage core adapter
【单选题】
Which statement regarding datastore clusters meets VMware’s recommended best practices?___
A. Clusters should contain only datastores presented from the same storage array.
B. Clusters should contain only datastores with equal hardware acceleration capability.
C. Clusters should contain only datastores with the same capacity.
D. Clusters should contain only datastores using the same connection method (iSCSI, FC, etc.).
【单选题】
What VM Monitoring setting would ensure that the maximum reset window for a virtual machine is 24 hours?___
A. Medium
B. Low
C. High
D. Normal
【单选题】
What is the default space threshold for vSphere Storage DRS?___
A. 80%
B. 70%
C. 90%
D. 95%
【单选题】
Which is the correct sequence to upgrade a vSphere infrastructure?___
A. vCenter Server>ESXi host> VMware Tools>VM compatibility
B. ESXi host>vCenter Server> VMware Tools>VM compatibility
C. vCenter host> ESXi host> VM compatibility> VMware Tools
D. ESXi host>vCenter Server> VM compatibility>VMware Tools
【单选题】
An administrator has a large boot from SAN cluster and wants to ensure consistent configuration by using host profiles. What special considerations are required for boot from SAN hosts?___
A. Change the “Device is shared clusterwide” setting to “false” in the host profile.
B. Verify that the boot LUN is correctly identified as the boot device in the host profile.
C. The boot from SAN device must report as a local device.
D. Host profiles are incompatible with boot from SAN hosts.
【单选题】
When using VMware Converter to import a Windows server and improve the consistency of the destination virtual machine, which optional step can be performed immediately prior to powering down the source server?___
A. Perform a final synchronization task.
B. Remove the server from the network.
C. Uninstall production applications.
D. Remove the server from the Active Directory domain.
【单选题】
Restoration of the vCenter Server Appliance is accomplished using which interface?___
A. vSphere Web Client
B. vSphere Client
C. vCenter Server Appliance Management Interface
D. vCenter Server Appliance GUI Installer
【单选题】
When attempting to migrate a virtual machine to another host in the same cluster, the error message, “Select a valid compute resource” returns. What could cause this error?___
A. Both hosts run different versions of ESXi.
B. Both hosts are not sharing the same datastore.
C. VMware Tools is not installed.
D. Virtual machine has an ISO attached.
【单选题】
When will vSphere Data Protection delete the expired backup image of a Platform Service Controller?___
A. Immediately after the retention period has expired.
B. After the expired backup image is restored.
C. During the next backup window following expiry.
D. During the next maintenance window following expiry.
【单选题】
Group A has permission to download files in Content Library. Group B does not have permission to download files in Content Library. If a user is a member of both groups, what will be the result?___
A. The user cannot download file from Content Library.
B. The user can download file from Content Library.
C. The user cannot access Content Library.
D. The user can access Content Library.
【单选题】
An administrator is trying to set up Host Partial Failure Response, but the Automated option is grayed out. What can the administrator change to enable the Automated option?___
A. Change the vSphere DRS Automation level to Partially Automated.
B. Change the vSphere DRS Automation level to Fully Automated.
C. Enable vSphere HA Host Monitoring.
D. Change the vSphere DPM Automation level to Automatic.
【单选题】
When you attempt to open a virtual machine console from the vSphere Web Client, the console does not connect. The following error message appears:<HTTP ERROR 404> <Problem accessin/.Reason: Not Found>. Why did not connect?___
A. Port 443 is in use.
B. Port 9443 is in use.
C. Port 8443 is in use.
D. Port 22443 is in use.
【单选题】
What new feature was introduced to the Content Library in vSphere 6.5?___
A. Mount an ISO directly from the Content Library.
B. Deploy a virtual machine from an OVF Package in a Content Library.
C. Upload a File from a URL to a Library Item.
D. Upload a File from a Local System to a Library Item.
【单选题】
How can an administrator exclude Encryption rights from a support engineer?___
A. Clone the role Virtual machine power user, remove Cryptographic operations privileges.
B. Clone the role Administrator and assign to the support engineer.
C. Clone the role Virtual machine power user and assign to the support engineer.
D. Clone the role No cryptography administrator and select privileges only for the support engineer.
【单选题】
The administrator must back up a vCenter HA deployment. Which component must be backed up?___
A. Passive node
B. Witness node
C. External database
D. Active node
