【单选题】
21在继电器中,NO接点是一种什么接点?___
A. 不使用接点
B. 不存在接点
C. 激磁后即开路的接点
D. 常开接点
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答案
D
解析
暂无解析
相关试题
【单选题】
22所谓2P的继电器,代表什么意思?___
A. 只有2个接点
B. 两相的负载
C. 两组电源
D. 2组c接点
【单选题】
23共阳极七段数码管显示器的驱动信号有何特色?___
A. 低电平点亮
B. 低电平不亮
C. 高电平点亮
D. 以上皆非
【单选题】
24在8×51的程序里,若要将某个输入/输出端口设置成输入功能,应如何处理?___
A. 先输出高电平到该输入/输出端口
B. 先输出低电平到该输入/输出端口
C. 先读取该输入/输出端口的状态
D. 先保存该输入/输出端口的状态
【单选题】
8×51提供几个外部中断和定时器/计数器中断?___
A. 2,2
B. 3,6
C. 2,3
D. 3,7
【单选题】
8×51的IP缓存器的功能如何?___
A. 设置中断优先级
B. 启动中断功能
C. 设置中断触发信号
D. 定义CPU的网址
【单选题】
28若要让采用低电平触发,则应如何设置?___
A. EX0=0
B. EX0=1
C. IT0=0
D. IT0=1
【单选题】
29在Keil µVision3里进行调试/仿真时,在哪里操作才能触动程序中断?___
A. 在Interrupt System
B. 在Cotorl Box对话框里
C. 直接单击魔术棒按钮即可
D. 直接按0键
【单选题】
30在8×51所提供的中断功能里,下列哪个优先级比较高?___
A. T1
B. RI/TI
C. T0
D. INT0
【单选题】
31在TCON缓存里,IE1的功能是什么?___
A. 触发 IE1中断
B. 指示IE1中断的标志
C. 提高IE1优先等级
D. 取消IE1中断
【单选题】
32在Keil C里,中断子程序与函数又何不同?___
A. 中断子程序不必声明
B. 函数不必声明
C. 中断子程序必须有形式参数
D. 中断子程序一定会有返回值
【单选题】
33若要同时启用INT0及INT1中断功能,则应如何设置?___
A. TCON=0×81
B. IE=0×85
C. IP=0×83
D. IE=0×03
【单选题】
35在8×51的Timer里,若使用Mode 0,其最大计数值为多少个机器周期?___
A. 65636
B. 8192
C. 1024
D. 256
【单选题】
36在12MHz的8×51系统里,哪一种方式一次可定时5ms?___
A. Mode 0及Mode 1
B. Mode 1及Mode 2
C. Mode 2及Mode 3
D. Mode3及Mode 1
【单选题】
37若要让Timer作为外部计数只用,应如何设置?___
A. Gate=0
B. Gate=1
C. C/=0
D. C/=1
【单选题】
39下列哪个不是8×51所提供的省电方式?___
A. PD方式
B. IDL方式
C. LP方式
D. 待机方式
【单选题】
89S51的看门狗有何作用?___
A. 重复执行程序
B. 找回遗失数据
C. 复位系统
D. 防止中毒
【单选题】
41若要启用WDT,则应依次填入WDTRST寄存器哪些数据?___
A. 0xe1、0xe2
B. 0xe1、0x1e
C. 0x1e、0xe1
D. 0x10、0x01
【单选题】
8×51的定时器,在下列哪种方式下具有自动加载功能?___
A. Mode0
B. Mode1
C. Mode2
D. Mode3
【单选题】
45下列哪种AD转换器的转换速度比较快?___
A. 双斜率型AD转换器
B. 比较型AD转换器
C. 连续计数式AD转换器
D. 逐渐接近式AD转换器
【单选题】
46下列哪种AD转换器的精密度比较高?___
A. 双斜率型AD转换器
B. 比较型AD转换器
C. 连续计数式AD转换器
D. 逐步逼近式AD转换器
【单选题】
47对于8×8 LED点阵而言,其中的LED个数及引脚各为多少?___
A. 64、16
B. 16、16
C. 64、12
D. 32、12
【单选题】
48在共阳极型8×8 LED点阵里,其阳极如何连接?___
A. 各行阳极连接到行引脚
B. 各列阳极连接到列引脚
C. 各行阳极连接到列引脚
D. 各列阳极连接到行引脚
【单选题】
49在共阳极型8×8 LED点阵里,其阴极如何连接?___
A. 各行阴极连接到行引脚
B. 各列阴极连接到列引脚
C. 各行阴极连接到列引脚
D. 各列阴极连接到行引脚
【单选题】
50双色8×8 LED点阵的列引脚与行引脚各位多少?___
A. 12、12
B. 8、16
C. 16、8
D. 24、8
【单选题】
1. AA001 主视图、左视图中相应投形的高度( ).
A. j
B. jj
C. jjj
D. jjjj
【单选题】
三相电动势到达最大的顺序是不同的,这种达到最大值的先后次序,称三相电源的相序,相序为U-V-W-U,称为___。
A. 正序
B. 负序
C. 逆序
D. 相序
【单选题】
电路的作用是实现能量的传输和转换、信号的___和处理。
A. 连接
B. 传输
C. 控制
D. 传递
【单选题】
电阻器反映导体对电流起阻碍作用的大小,简称___。
A. 电动势
B. 功率
C. 电阻率
D. 电阻
【单选题】
___反映了在不含电源的一段电路中,电流与这段电路两端的电压及电阻的关系。
A. 欧姆定律
B. 楞次定律
C. 部分电路欧姆定律
D. 全欧姆定律
【单选题】
并联电路中的总电流等于各电阻中的___。
A. 倒数之和
B. 相等
C. 电流之和
D. 分配的电流与各电阻值成正比
【单选题】
串联电路中流过每个电阻的电流都___。
A. 电流之和
B. 相等
C. 等于各电阻流过的电流之和
D. 分配的电流与各电阻值成正比
【单选题】
___的一端连在电路中的一点,另一端也同时连在另一点,使每个电阻两端都承受相同的电压,这种联结方式叫电阻的并联。
A. 两个相同电阻
B. 一大一小电阻
C. 几个相同大小的电阻
D. 几个电阻
【单选题】
___的电阻首尾依次相连,中间无分支的联结方式叫电阻的串联。
A. 两个或两个以上
B. 两个
C. 两个以上
D. 一个或一个以上
【单选题】
电流流过负载时,负载将电能转换成___。
A. 机械能
B. 热能
C. 光能
D. 其他形式的能
【单选题】
电功的数学表达式不正确的是___。
A. W=Ut/R2t
B. W=UIt
C. W=U2t/Rt
D. W=I2Rt
【单选题】
测量电压时,电压表应与被测电路___。
A. 并联
B. 串联
C. 正接
D. 反接
【单选题】
测量电流时,万用表的接线方法与直流电流表一样,应把万用表___在电路中。测量直流电压时,应把万用表与被测电路并联。
A. 串联
B. 并联
C. 正接
D. 反接
【单选题】
串联电路中各电阻两端电压的关系是___。
A. 各电阻两端电压相等
B. 阻值越小两端电压越高
C. 阻值越大两端电压越高
【单选题】
确定正弦量的三要素为 ___。
A. 相位、初相位、相位差
B. 最大值、频率、初相角
C. 周期、频率、角频率
【单选题】
纯电容元件在电路中___电能。
A. 储存
B. 分配
C. 消耗
推荐试题
【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.
【多选题】
An administrator is creating a new Virtual SAN cluster on a Layer 2 network. There is an existing Virtual SAN cluster on the same Layer 2 network. Which two actions would allow the new Virtual SAN cluster to coexist with the older cluster? (Choose two.)___
A. Change the default Multicast Address on the new Virtual SAN cluster.
B. Change the default Unicast Address on the new Virtual SAN Cluster.
C. Create a separate VLAN for each cluster.
D. Create an ARP Alias for the Virtual SAN VMkernel Network Adapter.
【多选题】
A vCenter Operations Manager 5.7 environment is upgraded to vRealize Operations. After the upgrade, the analytics services fail to start. Which three steps must be taken to resolve the problem? (Choose three.)___
A. Take the vRealize Operations cluster offline.
B. Delete the activity persistence files.
C. Bring the cluster back online.
D. Remove any unresponsive nodes.
E. Stop the CaSA service.
【多选题】
An organization has an ESXi 6.x host that contains two resource pools. The host is being relocated to a DRS cluster. What two actions can be taken to integrate the host into the cluster, and what would happen to the existing ESXi resource pool hierarchy as a result? (Choose two.)___
A. Place all of the host's virtual machines into the DRS cluster root resource pool. The resource pools present on the host will be deleted.
B. Create a resource pool for the ESXi host's virtual machines and resource pools. The resource pools present on the host will be deleted.
C. Place all of the host's virtual machines into the DRS cluster root resource pool. The resource pools present on the host will be preserved.
D. Create a resource pool for the
E. SXi host's virtual machines and resource pools. The resource pools present on the host will be preserved.