【单选题】
可编程序控制器在输入端使用了___，来提高系统的抗干扰能力。
A. 晶闸管
B. 继电器
C. 晶体管
D. 光电耦合器
查看试卷，进入试卷练习
微信扫一扫，开始刷题
相关试题
【单选题】
PLC梯形图编程时，输出继电器的线圈并联在___。
【单选题】
在FX2N PLC中，T200的定时精度为___。
A. 1ms
B. 10ms
C. 100ms
D. 1s
【单选题】
将程序写入可编程序控制器时，首先将___清零。
A. 计数器
B. 存储器
C. 计时器
D. 计算器
【单选题】
对于可编程序控制器电源干扰的抑制，一般采用隔离变压器和___ 来解决。
A. 直流发电机
B. 交流整流器
C. 交流滤波器
D. 直流滤波器
【单选题】
PLC外部环境检查时，当湿度过大时应考虑装___。
A. 除尘器
B. 风扇
C. 空调
D. 加热器
【单选题】
根据电动机顺序启动梯形图，下列指令正确的是___。
A. ORI Y001
B. ANDI T20
C. AND X001
D. AND X002
【单选题】
根据电动机自动往返梯形图，下列指令正确的是___。
A. LDI X002
B. ORI Y002
C. AND Y001
D. ANDI X003
【单选题】
对于晶体管输出型PLC，要注意负载电源为___，并且不能超过额定值。
A. AC600V
B. DC220V
C. DC24V
D. AC220V
【单选题】
变频器是通过改变交流电动机定子电压、频率等参数来___的装置。
A. 调节电动机转速
B. 调节电动机转矩
C. 调节电动机功率
D. 调节电动机性能
【单选题】
交—交变频装置通常只适用于 ___拖动系统。
A. 低速大功率
B. 高速大功率
C. 低速小功率
D. 高速小功率
【单选题】
在SPWM逆变器中主电路开关器件较多采用___。
A. MCT
B. 普通晶闸管
C. GTO
D. IGBT
【单选题】
FR-A700系列是三菱___变频器。
A. 节能型轻负载
B. 水泵和风机专用型
C. 多功能高性能
D. 经济型高性能
【单选题】
变频调速时电压补偿过大会出现___情况。
A. 负载重时，不能带动负载
B. 负载轻时，电流过小
C. 负载轻时，电流过大
D. 电机转矩过小，难以启动
【单选题】
负载不变情况下，变频器出现过电流故障，原因可能是：___。
A. 负载过重
B. 电源电压不稳
C. 转矩提升功能设置不当
D. 斜波时间设置过长
【单选题】
异步电动机的启动电流与启动电压成正比，启动转矩与启动___成正比。
A. 电流
B. 电压
C. 电流的二次方
D. 电压的二次方
【单选题】
软启动器的晶闸管调压电路组件主要由动力底座、___、限流器、通信模块等选配模块组成。
A. 控制单元
B. Profibus模块
C. 隔离器模块
D. 热过载保护模块
【单选题】
西普STR系列___软启动器，是内置旁路、集成型。
【单选题】
就交流电动机各种启动方式的主要技术指标来看，性能最佳的是___。
A. 变频启动
B. 软启动
C. 串电阻启动
D. 串电感启动
【单选题】
软启动器的功能调节参数有： ___、启动参数、停车参数。
A. 运动参数
B. 电阻参数
C. 电子参数
D. 软启动
【单选题】
软启动器的主电路采用___交流调压器，用连续地改变其输出电压来保证恒流启动。
A. 晶闸管变频控制
B. 晶闸管PWM控制
C. 晶闸管相位控制
D. 晶闸管周波控制
【单选题】
凝露的干燥是为了防止因潮湿而降低软启动器的___，及其可能造成的危害。
A. 使用效率
B. 绝缘等级
C. 接触不良
D. 散热效果
【单选题】
光电开关的接收器根据所接收到的光线强弱对目标物体实现探测，产生___。
A. 频率信号
B. 开关信号
C. 压力信号
D. 警示信号
【单选题】
光电开关可以___、无损伤地迅速检测和控制各种固体、液体、透明体、黑体、柔软体、烟雾等物质的状态。
A. 电磁感应
B. 非接触
C. 小电流
D. 高亮度
【单选题】
当检测远距离的的物体时，应优先选用___光电开关。
A. 光纤式
B. 槽式
C. 漫反射式
D. 对射式
【单选题】
光电开关的配线不能与___放在同一配线管或线槽内。
A. 光纤线
B. 网络线
C. 动力线
D. 电话线
【单选题】
高频振荡电感型接近开关主要由感应头、振荡器、开关器、___等组成。
A. 发光二极管
B. 光电三极管
C. 继电器
D. 输出电路
【单选题】
高频振荡电感型接近开关的感应头附近有金属物体接近时，接近开关___。
A. 涡流损耗减少
B. 无信号输出
C. 振荡减弱或停止
D. 振荡电路工作
【单选题】
当检测体为___时，应选用电容型接近开关。
A. 透明材料
B. 金属材料
C. 非金属材料
D. 不透明材料
【单选题】
选用接近开关时应注意对工作电压、负载电流、响应频率、___等各项指标的要求。
A. 检测电流
B. 工作速度
C. 检测功率
D. 检测距离
【单选题】
磁性开关可以由___构成。
A. 二极管和电磁铁
B. 接触器和按钮
C. 永久磁铁和干簧管
D. 三极管和永久磁铁
【单选题】
磁性开关中的干簧管是利用___来控制的一种开关元件。
A. 电流信号
B. 温度信号
C. 磁场信号
D. 压力信号
【单选题】
磁性开关用于高温高压场所时应选___的器件。
A. PP、PVDF材质
B. 多层纸质
C. 金属材质
D. 晶体材质
【单选题】
磁性开关在使用时要注意磁铁与___之间的有效距离在10mm左右。
【单选题】
增量式光电编码器主要由光源、码盘、___、光电检测器件和转换电路组成
A. 光电三极管
B. 脉冲发生器
C. 检测光栅
D. 运算放大器
【单选题】
增量式光电编码器每产生一个___就对应于一个增量位移。
A. 输出电压信号
B. 输出光脉冲
C. 输出脉冲信号
D. 输出电流信号
【单选题】
增量式光电编码器由于采用相对编码，因此掉电后旋转角度数据___，需要重新复位。
A. 变大
B. 不会丢失
C. 变小
D. 会丢失
【单选题】
增量式光电编码器根据信号传输距离选型时要考虑___。
A. 输出信号类型
B. 电源频率
C. 环境温度
D. 空间高度
【单选题】
可编程序控制器采用大规模集成电路构成的___和存储器来组成逻辑部分。
A. 运算器
B. 微处理器
C. 控制器
D. 累加器
【单选题】
可编程序控制器系统由基本单元、___、编程器、用户程序、程序存入器等组成。
A. 扩展单元
B. 键盘
C. 鼠标
D. 外围设备
【单选题】
在一个程序中，同一地址号的线圈___次输出，且继电器线圈不能串联只能并联。
A. 无限
B. 只能有一
C. 只能有二
D. 只能有三
推荐试题
【多选题】
What are two advanced features of the Cisco AMp solution for endpoints ___
A. contemplation
B. foresight
C. sandboxing
D. reputation
E. reflection
【多选题】
Which two characteristics of RADIUS are true？___
A. It encrypts only the password between user and server.
B. It uses TCP ports 1812/1813
C. It uses UDP ports 1812/1813.
D. It uses UDP port 49
E. It uses TCP port 49
【多选题】
What are two challenges of using a network-based IPS？ ___
A. It is unable to determine whether a detected attack was successful
B. It requires additional storage and proce ssor capacity on syslog servers
C. As the network expands， it requires you to add more sensors.
D. It is unable to detect attacks across the entire network
E. It must support multiple operating systems.
【多选题】
What are two default be haviors of the traffic on a zone-based firewall？___
A. Traffic within the self -zone uses an im plicit deny all.
B. All traffic between zones is implicitly blocked
C. Communication is allowed between interfadAss that are members of the same zone
D. Communication is blocked between interfaces that are members of the same zone
E. The CBAC rules that are configured on router interfaces apply to zone interfaces
【多选题】
Which two advantages does the on-premise model for MDM deployment have over the cloud-based model？___
A. The on-premise model is easier and faster to de ploy than the cloud-based model
B. The on-premise model is more scalable than the cloud-based model
C. The on-premise model is generally less expensive than the cloud-based model
D. The on-premise model generally has less latency than the cloud- based model.
E. The on-premise model provides more control of the MDM solution than the cloud
【多选题】
Which two actions can an end usts take to manage a lost or stolen device in Cisco ISE？ ___
A. Activate Cisco ISE End point Protection Services to quarantine the device.
B. Add the mac address of the device to a list of blacklisted devices
C. Force the device to be locked with a PIN
D. Request revocation of the digital certificate of the device.
E. Reinstate a device that the user previously marked as lost or stolen
【多选题】
Which two problems can arise when a proxy firewall serves as the gateway between networks？___
A. It can prevent content caching
B. It can limit application support
C. It is unable to prevent direct connections to other networks
D. It can cause reduced throughput.
E. It is unable to provide antivirus protection
【多选题】
When using the Adaptive Security Device Manager（ASDM）， which two methods are available to add a new root certificate？___
A. Use sCep
B. Install from SFTP server
C. Install from a file
D. Use Https
E. Use LDAP
【多选题】
Which two are considered basic security principles？___
A. Accountability
B. Redundancy
C. High Availabilit
D. Integrity
E. Confidentiality
【多选题】
Which two roles of the Cisco WSA are true？___
A. IPS
B. firewall
C. antispam
D. web proxy
E. URL filter
【单选题】
Which next-generation encryption algorithm supports four variants？___
A. SHA-2
B. SHA-1
C. MD5
D. HMAC
【单选题】
What aims to remove the abil ity to deny an action？___
A. Non-Repudiation
B. Accountability
C. Integrity
D. Deniability
【单选题】
Which statements about the native VLAN is true ？___
A. It is susceptible to VLAN hopping attacks.
B. It is the Cisco recommended VLAN for switch-management traffic
C. It is most secure when it is a ssigned to vLAn 1.
D. It is the cisco-recomme nded vlan for user traffic
【单选题】
There are two versions of IKE:IKEv1 and IKEv2. Both IKEv1 and IKEv2 protocols operate in phases IKEv1 operates in two phases. IKEv2 operates in how many phases？___
【单选题】
What does the dh group refer to？___
A. length of key for hashing C
B. length of key for encryption
C. tunnel lifetime key
D. length of key for key exchange
E. length of key for authentication
【单选题】
Which path do you follow to enable aaa through the SDM ？___
A. Configure Tasks > AAA
B. Configure > Addition Authentication > AAA
C. Configure > AAA
D. Configure > Additional Tasks > AAA
E. Configure Authentication > AAA
【单选题】
which technology cloud be used on top of an MPLS VPN to add confidentiality ？___
A. IPsec
B. 3DES
C. AES
D. SSL
【单选题】
Which term is most closely aligned with the basic purpose of a SIEM solution? ___
A. Non-Repudiation
B. Accountability
C. Causality
D. Repudiation
【单选题】
You have just deployed SNMPv3 in your environment， Your manager asks you to make sure that our SNMP agents can only talk to the SNMP Manager. What would you configure on your SNMI agents to satisfy this request？___
A. A SNMP View containing the SNMP managers
B. Routing Filter with the SNMP managers in it applied outbound
C. A standard ACL containing the SNMP managers applied to the SNMP configuration
D. A SNMP Group containing the SNMP managers
【单选题】
Which feature prevents loops by moving a nontrunking port into an errdisable state when a BPDU is received on that port？___
A. BPDU filte
B. DHCP snooping
C. BPDU guard
D. Port Fast
【单选题】
Which command enables port security to use sticky MAC addresses on a switch？___
A. switchport port-security violation restrict
B. switchport port-security mac-address sticky
C. switchport port-security violation protect
D. switchport port-security
【单选题】
When you edit an IPS subsignature， what is the effect on the parent signature and the family of subsignatures？___
A. The change applies to the parent signature and the entire family of subsignatures
B. The change applies to the parent signature and the subsignature that you edit
C. The change applies only to subsignatures that are numbered sequentially after the subsignature that you edit
D. Other signatures are unaffected， the change applies only to the subsignature that you dit
【单选题】
Which type of mechanism does Cisco FirePOWER de ploy to protect ag detected moving across other networks？___
A. antivirus scanning
B. policy-based
C. reputation-based
D. signature-based
【单选题】
What action must you take on the ise to blacklist a wired device？___
A. Locate the switch through which the device is connected and push an a cl restricting all access by the device
B. Issue a CoA request for the de vice's mac address to each access switch in the network
C. Revoke the device's certificate so it is unable to authenticate to the network
D. Add the device's MAc address to a list of black listed devices
【单选题】
Which type of firewall can perform deep packet inspection？___
A. packet-filtering firewall
B. stateless firewall
C. application firewall
D. personal firewall
【单选题】
What is the main purpose of Control Plane Policing？___
A. to prevent exhaustion of route-proce ssor resources
B. to organize the egress packet queues
C. to define traffic classes
D. to maintain the policy map
【单选题】
Which attack can be prevented by OSPF authentication？___
A. smurf attack
B. IP spoofing attack
C. denial of service attack
D. buffer overflow attack
【单选题】
What is the best definition of hairpinning？___
A. ingress traffic that traverses the outbound interface on a device
B. traffic that enters one interface on a device and that exits through another interface
C. traffic that enters and exits a device through the same interface
D. traffic that tunnels through a device interface
【单选题】
Which SNMPv3 security level provides authentication using HMAC with MD5， but does not use encryption？___
A. authPriv
B. authNo Priv
C. noAuthNoPriv
D. NoauthPriv
【单选题】
You have implemented a dynamic blacklist， using security intelligence to block illicit network activity. However， the blacklist contains several approved connections that users must access for usiness pur poses. Which action can you take to retain the blacklist while allowing users to access the approve d sites？___
A. Create a whitelist and manually add the approved addresses.
B. Disable the dynamic blacklist and deny the specif ic address on a whitelist while permitting the others
C. Edit the dynamic blacklist to remove the approved addresses
D. Disable the dynamic blacklist and create a static blacklist in its place
【单选题】
When connecting to an external resource,you must change a source IP address to use one IP address from a range of 207.165.201.1 to 207.165.1.30. Which option do you implement ?___
A. dynamic source NAT that uses an IP ad dress as a mapped source
B. static destination NAT that uses a subnet as a real de stination
C. dynamic source NAT that uses a range as a mapped source
D. static destination NAT that uses a subnet as a real source
【单选题】
Refer to the exhibit. 【nat（ins，any）dynamic interface】Which ty pe of NaT is configured on a Cisco ASA？___
A. dynamic NAT
B. source identity NAT
C. dynamic PAT
D. identity twice NAT
【单选题】
Which mitigation technology for web-based threats prevents the removal of confidential data from the network？___
A. CTA
B. DCA
C. AMP
D. DLP
【单选题】
Refer to the exhibit. What is the effect of the given configuration？___
A. It establishes the preshared key for the switch
B. It establishes the preshared key for the firewall.
C. It establishes the preshared key for the Cisco ISE appliance
D. It establishes the preshared key for the router.
【多选题】
What are two major considerations when choosing between a SPAN and a TAP when plementing IPS？___
A. the type of analysis the iS will perform
B. the amount of bandwidth available
C. whether RX and TX signals will use separate ports
D. the way in which media errors will be handled
E. the way in which dropped packets will be handled
【多选题】
What are two direct-to-tower methods for redirecting web traffic to Cisco Cloud Web Security？___
A. third-party proxies
B. Cisco Catalyst platforms
C. Cisco NAC Agent
D. hosted PAC files
E. CiSco ISE
【多选题】
Which three descriptions of RADIUS are true？ ___
A. It uses TCP as its transport protocol.
B. Only the password is encrypted
C. It supports multiple transport protocols
D. It uses UDP as its transport protocol
E. It combines authentication and authorization
F. It separates authentication，authorization，and accounting
【多选题】
Which two configurations can prevent VLAN hopping attack from attackers at VLAN 10？___
A. using switchport trunk native vlan 10 command on trunk ports
B. enabling BPDU guard on all access ports
C. creating VLAN 99 and using switchport trunk native vlan 99 command on trunk ports
D. applying ACl between VLAN
E. using switchport mode access command on all host ports
F. using switchport nonegotiate command on dynamic desirable ports
【多选题】
What are two features of transparent firewall mode ___
A. It conceals the presence of the firewall from attackers
B. It allows some traffic that is blocked in routed mode
C. It enables the aSA to perform as a router.
D. It acts as a routed hop in the network.
E. It is configured by default
【多选题】
Which two models of A sa tend to be used in a data center？___
A. 5555X
B. 5585X
C. ASA service module
D. 5512X
E. 5540
F. 5520
