【单选题】
38为了使放大器带负载能力强,一般引入___负反馈。
A. 电压
B. 电流
C. 串联
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答案
A
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相关试题
【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
A. 电流
B. 电压
C. 并联
D. 串联
【单选题】
42为了稳定输出电流,采用___负反馈。
A. 电流
B. 电压
C. 并联
D. 串联
【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
【单选题】
48分析运放的“虚断”是指是___。
A. U-≈U+
B. I-≈I+≈0
C. I-≈I+
D. U-≈U+≈0
【单选题】
51两级放大电路,Au1=-40,Au2=-50,若输入电压U1=5mv,则输出电压Uo为 ___
A. -200mv;
B. -250mV;
C. 10V;
D. 100V
【单选题】
52通用型集成运放的输入级多采用___。
A. 共基接法
B. 共集接法
C. 共射接法
D. 差分接法
【单选题】
53理想运放的两个重要性质是___。
A. 虚短与虚地
B. 虚断与虚短
C. 断路与短路
【单选题】
54振荡器的输出信号最初由___而来的。
A. 基本放大器
B. 选频网络
C. 干扰或噪声信号
【单选题】
55产生正弦波自激震荡的稳定条件是___。
A. 引入正反馈
B. |AF|≥1
C. AF=1
【单选题】
56从结构上来看,正弦振荡电路是一个 ___ 。
A. 有输入信号的负反馈放大器;
B. 没有输入信号的带选频网络的正反馈放大器;
C. 没有输入信号的不带选频网络的正反馈放大器。
【单选题】
57对频率稳定度要求较高的振荡器,要采用: ___ 。
A. LC振荡电路;
B. RC振荡电路;
C. RL振荡电路;
D. 石英晶体振荡电路。
【单选题】
58在甲类、乙类、甲乙类放大电路中,其导通角分别为___
A. 小于180 O、180 O、360O
B. 360O、180 O、小于180 O。
C. 180 O、小于180 O、360O
【单选题】
W78XX系和列W79XX系列引脚对应关系为 ___ 。
A. 一致;
B. 1脚与3脚对调,2脚不变;
C. 1、2对调。
【单选题】
60两个β相同的晶体管组成复合管后,其电流放大系数约为 ___ 。
A. β
B. β2
C. 2β
D. 1+β
【单选题】
1三极管的开关特性是___。
A. 截止相当于开关接通
B. 放大相当于开关接通
C. 饱和相当于开关接通
D. 截止相当于开关断开,饱和相当于开关接通
【单选题】
2数字集成门电路,目前生产最多应用最普遍的门电路是___
A. 与门
B. 或门
C. 非门
D. 与非门
【单选题】
3由一个三极管组成的基本门电路是___。
A. 与门
B. 非门
C. 或门 、D异或门
【单选题】
4在遥测系统中,需通过___把非电量的变化转变为电信号。
A. 电阻器、
B. 电容器、
C. 传感器、
D. 晶体管
【单选题】
5半导体发光数码管由___个条状的发光二极管组成。
A. 5
B. 6
C. 7
D. 8
【单选题】
6“有0出1,全1出0”属于___
A. 与逻辑
B. 或逻辑
C. 非逻辑
D. 与非逻辑
【单选题】
7二进制数11101转化成十进制数为___
A. 29
B. 57
C. 4
D. 15
【单选题】
8TTL系列集成芯片工作电源电压的典型值是___。
A. 18V
B. 5V
C. 3V
D. 10V
【单选题】
9能实现Y=0的电路是___图。
A. 图
B. 图
C. 图
D. 图
【单选题】
10以下表达式中符合逻辑运算法则的是___。
A. 1+1=10
B. A+A=2A
C. A+=1.
D. A·=1
【单选题】
11对于TTL与非门闲置输入端的处理,不可以___
A. 与有用输入端并联
B. 通过电阻3kΩ接电源
C. 接地
D. 接电源
【单选题】
12十线/四线优先编码器74LS147所用的输出代码为___。
A. 5421BCD码
B. 格雷码
C. 8421BCD码
D. 余3码
【单选题】
13为实现“线与”逻辑功能,应选用___
A. OC门
B. 与门
C. 异或门
D. 同或门
【单选题】
14和逻辑式A+ABC相等的式子是___
A. c
B. bc
C. abc
D. a
【单选题】
15逻辑函数的表示方法中具有唯一性的是___
A. 真值表
B. 表达式
C. 逻辑图
D. 卡诺图
【单选题】
16与模拟电路相比,数字电路主要的优点是___。
A. 容易设计
B. 通用性强
C. 抗干扰能力强
【单选题】
17某门电路的输入输出波形如图所示,试问此逻辑门的功能是___。
A. 与非
B. 或非
C. 异或
D. 同或
【单选题】
18以下电路中常用于总线应用的有___。
A. TSL门
B. OC门
C. 漏极开路门
D. CMOS与非门
【单选题】
逻辑表达式Y=AB可以用___实现。
A. 正或门
B. 正非门
C. 正与门
D. 负或门
【单选题】
20TTL电路在正逻辑系统中,以下各种输入中___相当于输入逻辑“0”。
A. 悬空
B. 通过电阻2.7kΩ接电源
C. 通过电阻2.7kΩ接地
D. 通过电阻510Ω接地
【单选题】
21对于TTL与非门闲置输入端的处理,不可以___。
A. 接电源
B. 通过电阻3kΩ接电源
C. 接地
D. 与有用输入端并联
【单选题】
22STTL数字集成电路与CMO数字集成电路相比突出的优点是___。
A. 微功耗
B. 高速度
C. 高抗干扰能力
D. 电源范围宽
推荐试题
【单选题】
An administrator needs to verify that vMotion operations can be performed in a vSphere data center.What round trip time (RTT) latency is the maximum value that will allow vMotion operations to succeed? ___
A. 50ms RTT
B. 100ms RTT
C. 150ms RTT
D. 200ms RTT
【单选题】
A storage administrator has reported that full utilization of all bandwidth from an ESXi 6.x host is not being seen. In troubleshooting the issue, the Adapter details are shown in the Exhibit. Based on the exhibit, what is cause of the issue? ___
A. The array is not setup to use the correct multipathing policy.
B. There are no virtual machines on the ESXi host.
C. Not all links are used because a path is disabled.
D. Another path needs to be configured.
【单选题】
An administrator is migrating a powered-on virtual machine, as shown in the exhibit. Which option should be selected to perform a Storage vMotion of the VM? ___
A. Change storage only
B. Change VM compute resource only
C. Change both compute resource and storage, changing the compute resource first.
D. Change both compute resource and storage, changing the storage resource first.
【单选题】
An administrator is attempting to enable Storage I/O Control on a datastore, but it is failing. What is the likely reason for this failure? ___
A. The host is connected to a datastore is running on ESX 4.0.
B. The host is connected to a Fibre Channel storage array.
C. The datastore has multiple extents.
D. The datastore is managed by a single vCenter Server.
【单选题】
A mission-critical virtual machine built on vSphere 4.1 needs to be moved to an ESXi 6.x host.Which virtual hardware version is needed to move the virtual machine without upgrading? ___
A. 6
B. 7
C. 10
D. 11
【单选题】
An administrator is analyzing a virtual machine as shown in the Exhibit. What is the current long term risk for this virtual machine? ___
A. The virtual machine may run out of memory before April 27.
B. The virtual machine may continue to function after April 27.
C. The virtual machine has adequate memory configured for operation for the next 120 days.
D. The virtual machine has adequate memory reservation configured for operation for the next 120 days.
【单选题】
An administrator is monitoring a High Availability (HA) and Distributed Resource Scheduler (DRS) enabled cluster and has noticed that virtual machines in the cluster are being migrated without user intervention. Why is this happening? ___
A. The DRS Automation level is set to Fully Automated.
B. The Automation level is set to Automatic.
C. The
D. PM Threshold is set to Aggressive.
【单选题】
An administrator attempts to migrate a suspended virtual machine to a newly deployed vSphere 6.x cluster. The compatibility check fails. What condition could cause this behavior?___
A. The new vSphere 6.x cluster is running Intel CPUs instead of AMD CPUs.
B. A suspended virtual machine cannot be migrated.
C. The hardware virtualization feature of the CPU is not enabled on the new hosts.
D. A vSphere Distributed Switch is required to migrate a suspended virtual machine.
【单选题】
A vSphere administrator has been using vSphere in evaluation mode and now wants to deploy an environment that provides the same features. Which edition of vSphere provides similar functionality to evaluation mode? ___
A. Enterprise Plus
B. Enterprise
C. Standard
D. Essentials
【单选题】
A vSphere administrator has been using vSphere in evaluation mode and now wants to deploy an environment that provides the same features. Which edition of vSphere provides similar functionality to evaluation mode? ___
A. Enterprise Plus
B. Enterprise
C. Standard
D. Essentials
【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.