【单选题】
自动控制系统正常工作的首要条件是___。
A. 系统闭环负反馈控制
B. 系统恒定
C. 系统可控
D. 系统稳定
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答案
C
解析
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相关试题
【单选题】
反馈控制系统主要由___、比较器和控制器构成，利用输入与反馈两信号比较后的偏差作为控制信号来自动地纠正输出量与期望值之间的误差，是一种精确控制系统。
A. 给定环节
B. 补偿环节
C. 放大器
D. 检测环节
【单选题】
实际的自控系统中，RC串联网络构成微分电路并不是纯微分环节，相当一个___，只有当RC<<1时，才近似等效为纯微分环节。
A. 微分环节与积分环节相串联
B. 微分环节与比例环节相串联
C. 被分环节与惯性环节相串联
D. 微分环节与延迟环节相串联
【单选题】
在带P1调节器的无静差直流调速系统中，可以用___来抑制突加给定电压时的电流冲击，以保证系统有较大的比例系数来满足稳态性能指标要求。
A. 电流截止正反馈
B. 电流截止负反馈
C. 电流正反馈补偿
D. 电流负反馈
【单选题】
对采用Pl调节器的无静差调速系统，若要提高系统快速响应能力，应___。
A. 整定P参数，减小比例系数
B. 整定I参数，加大积分系数
C. 整定P参数，加大比例系数
D. 整定l参数，减小积分系数
【单选题】
转速负反馈有静差调速系统中，当负载增加以后，转速要下降，系统自动调速以后，使电动机的转速___。
A. 以恒转速旋转
B. 等于原来的转速
C. 略低于原来的转速
D. 略高于原来的转速
【单选题】
闭环负反馈直流调速系统中，电动机励磁电路的电压纹被对系统性能的影响，若采用___自我调节。
A. 电压负反馈调速时，能
B. 转速负反馈调速时，不能
C. 转速负反馈调速时，能
D. 电压负反馈加电流正反馈补偿调速时，能
【单选题】
转速负反馈直流调速系统具有良好的抗干扰性能，它能有效地抑制___。
A. 给定电压变化的扰动
B. 一切前向通道上的扰动
C. 反馈检测电压变化的扰动
D. 电网电压及负载变化的扰动
【单选题】
在电压负反馈调速系统中，电流正反馈环节实质为转速降补偿控制，因此是___
A. 有静差调速系统
B. 无静差调速系统
C. 全补偿时是无静差调速系统
D. 难以确定静差有无的调速系统
推荐试题
【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
【单选题】
What is the supported protocol to perform remote L3 traffic monitoring in vSphere 6.5?___
A. VXLAN
B. ERSPAN
C. RSPAN
D. SPAN
【单选题】
What are the minimum hardware requirements for a Windows vCenter Server with embedded PSC that manages a “Small” environment?___
A. 2vCPUs, 16 GB RAM
B. 4 vCPUs, 16 GB RAM
C. 2 vCPUs, 10 GB RAM
D. 4 vCPUs, 10 GB RAM
【单选题】
Which port is used for communication between ESXi and vSphere Data protection?___
A. 80
B. 443
C. 902
D. 22
