【单选题】
2000kW 及以上大容量的高压电机,普遍采用 ___ 代替电流速断保护。
A. 过负荷保护
B. 低电压保护
C. 纵差动保护
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相关试题
【单选题】
安装单位号11D 的 1 号端子 11n3 属于 ___。
A. 设备文字符号
B. 回路编号
C. 相对编号
【单选题】
下列 ___不属于电力系统中的事故。
A. 对用户少送电
B. 电能质量降低到不能允许的程度
C. 过负荷
【单选题】
差动保护属于按___ 分类。
A. 被保护的对象
B. 保护原理
C. 保护所起作用
【单选题】
___ 可以将电力系统的一次大电流按一定的变比变换成二次较小电流,供给测量表计和继电器。
【单选题】
当带电体有接地故障时,有故障电流流入大地,人在接地点周围两脚之间出现的电压称为 ___。
【单选题】
在检修变压器,要装设接地线时,应___ 。
A. 先装中相
B. 装接地端 ,再装导线端
C. 先装导线端 ,再装接地端
【单选题】
绝缘棒一般每___ 进行一次绝缘试验。
【单选题】
电工作业人员,应认真贯彻执行___ 的方针 ,掌握电气安全技术,熟悉电气安全的各项措施 ,预防事故的发生。
A. 安全第一、预防为主、综合治理
B. 安全重于泰山
C. 科学技术是第一生产力
【单选题】
下列 ___ 属于基本安全用具。
A. 绝缘棒、绝缘夹钳
B. 绝缘手套、绝缘靴
C. 携带型接地线、临时遮栏
【单选题】
人体发生单相触电时,作用于人体的电压是___
【单选题】
发生高压设备、导线接地故障时,在室内人体不得接近接地故障点___ 以内。
【单选题】
发生高压设备、导线接地故障时,在室外人体不得接近接地故障点___ 以内。
【单选题】
下列 ___安全用具是在电气操作中使用的基本安全用具。
A. 绝缘手套、验电器
B. 绝缘鞋、绝缘站台
C. 验电器、绝缘夹钳
【判断题】
甲乙两设备采用相对编号法, 是指在甲设备的接线端子上标出乙设备接线端子编号, 乙设备的接线端子上标出甲设备的接线端子编号
【判断题】
一般以全年平均供电时间占全年时间的百分数衡量供电的可靠性
【判断题】
导线必须要有足够的机械强度，即导线的实际应力应小于导线的容许应力
【判断题】
雷电的机械效应破坏力强大, 可使电力设施毁坏, 使巨大的建筑物倒塌, 造成电力中断, 家毁人亡等。
【判断题】
架空线路故障，当继电保护动作后，自动重合闸装置使断路器自动合闸
【判断题】
变压器电源侧发生故障时，变压器的瓦斯保护装置应动作
【判断题】
用户变电站或配电室进行并路刀闸时，不应自行停用进线保护
【判断题】
对于电路中的任意一个回路，回路中各电源电动势的代数和等于各电阻上电压降的代数和
【判断题】
降压配电变压器的二次输出的额定电压要高于用电设备额定电压5%左右
【判断题】
并列运行的变压器，若接线组别不同，会造成短路故障
【判断题】
工作票是准许在电气设备上工作的书面命令，是执行保证安全技术措施的书面依据，一般有三种格式
【判断题】
在均匀磁场中，磁感应强度B与垂直于他的截面积S 的乘积，叫做该截面的磁通密度
【判断题】
在工期允许的允许的情况下，应该首先敷设高压电力电缆，其次敷设低压动力电缆，最后敷设控制电缆和信号电缆
【判断题】
隔离开关只能用来将电气设备与带电体隔离
【判断题】
箱式变压器内的一次设备为全封闭高压开关柜，产品无裸露带电部分，为全封闭、全绝缘结构，完全能达到零触电事故
【判断题】
2000KW及以上大容量的高压电动机，常采用过流速断保护
【判断题】
电气设备发生火灾时，严禁使用能导电的灭火剂进行带电灭火
【判断题】
工作票签发人不得兼任所签发工作票的工作负责人
【判断题】
变压器正常运行时，上层油温一般不允许超过85℃
【判断题】
为防止跨步电压伤人，防直击雷接地装置距建筑物出入口和人行道边的距离不应小于3 米， 距电气设备装置要求在 5 米以上
推荐试题
【单选题】
Refer to the exhibit， A Network Secur ity administrator check the ASa firewall NAT policy table rith show nat command， which statement is fails？___
A. There are only reverse translation matches for the REAL SERvER object
B. First policy in the Section 1 is a dynamic nat entry defined in the object configuration
C. NAT policy in section 2 is static entry de fined in the object configuration
D. Translation in Section 3 used when a connection does not matches any entries in first two sections
【单选题】
What is true of an aSa in transparent mode ?___
A. It supports OSPF
B. It requires an IP address for each interface
C. It requires a management IP address
D. It allows the use of dynamic NaT
【单选题】
What is the effect of the ip scp server enable command？___
A. It references an access list that allows specific SCP servers
B. It allows the router to initiate requests to an SCP server
C. It allows the router to become an SCP server
D. It adds SCP to the list of allowed copy functions
【单选题】
How can you mitigate attacks in which the attacker attaches more than one vLan tag to a packet？___
A. Assign an access VLAN to every active port on the switch
B. Disable Ether Channel on the switch
C. Explicitly identity each VLAN allowed across the trunk
D.
E. nable transparent VTP on the switch
【单选题】
Which technology can you implement to centrally mitigate potential threats when users on your network download files that might be malicious？___
A. Enable file-reputation services to inspect all files that traverse the company network and block files with low reputation scores
B. Verify that the compa ny IpS blocks all known malicious website
C. Verity that antivirus software is installed and up to date for all users on your network
D. Implement URL filtering on the perimeter firewall
【单选题】
What is the most common implementation of PaT in a standard networked environment？___
A. configuring multiple external hosts to join the self zo ne and to communicate with one another
B. configuring multiple internal hosts to communicate outside of the network using the outside interface IP address
C. configuring multiple internal hosts to communicate outside of the network by using the inside interface IP address
D. configuring an any any rule to enable external hosts to communicate inside the network
【单选题】
Which component of a bYod architecture provides aAa services for endpoint access ?___
A. Integrated Services Router
B. access point
C. ASA
D. Identity Services
E. ngine
【单选题】
You are configuring a NAT rule on a Cisco ASA ,Which description of a mapped interface is true?___
A. It is mandatory for all firewall modes
B. It is optional in routed mode
C. It is optional in transparent mode
D. It is mandatory for ide ntity NAT only
【单选题】
Which description of the use of a private key is true ？___
A. The sender signs a message using the receivers private key
B. The sender signs a message using their private key
C. The sender encrypts a message using the receivers private key
D. The receiver decrypts a n15ssage using the sender's private key
【单选题】
Which mechanism does the FireAMP Connector use to avoid conflicts with other security applications such as antivirus products ?___
A. Virtualization
B. Containers
C. Sandboxing
D.
E. xclusions
【单选题】
Which network to pology de scribes multiple LANS in a gec? ___
A. SOHO
B. MAN
C. pan
D. CAN
【单选题】
Which statement represents a difference between an access list on an aSa versus an access list on a router？___
A. The asa does not support number access lists
B. The aSa does not support standard access list
C. The asa does not ever use a wildcard mask
D. The asa does not support extended access lists
【单选题】
Which command do you enter to verify the status and settings of an iKE Phase 1 tunnel？___
A. show crypto ipsec as output
B. show crypto isakmp
C. show crypto isakmp policy
D. show crypto ipsec transform
【单选题】
Which feature can help a router or switch maintain packet forwarding and protocol states despite an attack or heavy traffic load on the router or switch？___
A. service Policy
B. Control Plane Policing
C. Policy Map
D. Cisco
E. xpress
F. orwarding
【单选题】
Which STP feature can prevent an attacker from becoming the root bridge by immediately shutting down the interface when it receives a BPDU？___
A. root guard
B. Port Fast
C. BPDU guard
D. BPDU filtering
【单选题】
Which technology can best protect data at rest on a user system？___
A. full-disk encryption
B. IPsec tunnel
C. router ACL
D. network IPS
【多选题】
Which two primary security concerns can you mitigate with a BYOD solution ？___
A. schedule for patching the device
B. securing access to a trusted corporate network
C. compliance with applicable policies
D. connections to public Wi-Fi networks
E. device tagging and invento
【多选题】
choose five___
A. MD5————————inserure
B. DES————————insercure
C. SDES———————legacy
D. SHA-1———————legacy
E. HMAC-MD5—————legacy
【多选题】
Which two characteristics of symmetric encryption are true？___
A. It uses digital certificates
B. It requires more resources than asymmetric ancryption
C. It uses the same key to enctypt and decrupt traffic
D. It uses a public key and a pricate key to encrypt and decrypt traffic.
E. It is faster than asymmetric encryption
【多选题】
which two characteristics of PVLAN are true？___
A. Promiscuous porta can communicate with PVLAN ports.
B. Isolated ports cannot communicate with other ports on the same VLAN
C. Community ports have to be a part of the trunk.
D. They require VTP to be enabled in server mode
E. PVLAN ports can be configured as Ether Channel ports
【多选题】
What are two options for running Cisco SDM?___
A. Running SDM from a mobile device
B. Running SDM from within CiscoWorks
C. Running SDM from a router's flash
D. Running SDM from the Cisco web porta
E. Running SDM from a PC
【多选题】
Which two options are the primary deployment modeles for mobile device management？___
A. multisite
B. cloud-based
C. on premises
D. hybrid cloud basedo
E. single site
【多选题】
Drag the recommendation on the left to the Cryptographic algorithms on the right， Options will be used more than once.___
A. Avoid——————————————DES，MD5
B. Legacy——————————————SDES，SHA1，HMAC-MD5
【多选题】
Which two are valid types of vLans using PVLANS ?___
A. Community VLAN
B. Backup VLAN
C. Secondary VLAN
D. Isolated VLAN
E. Isolated VLAN
【多选题】
Which two commands are used to implement Resilient lOS Configuration ___
A. Secure boot-config
B. copy running-config tftp
C. copy flash:ios bin tftp
D. copy running-config startup-config
E. secure boot-image
【多选题】
Which two types of firewalls work at layer 4 and above ？___
A. Stateful inspection
B. Network Address Translation
C. Circuit-Level gateway
D. Static packet filter
E. Application Level firewall
【多选题】
Which two default settings for port security are true ？___
A. Violation is Protect
B. Violation is Restrict
C. Violation is Shutdown
D. Maximum number of MAC addresses is 2
E. Maximum number of MAC addresses is 1
【多选题】
Which two are characteristics of RADIUS？___
A. Uses UDP ports 1812 /1813
B. Uses TCP port 49
C. Uses UDP port 49
D.
E. ncrypts only the password between user and server
【多选题】
When setting up a site-to-site VPN with PSK authentication on a Cisco router， which two elements must be configured under crypto map？___
A. pfs
B. nat
C. reverse route
D. peer
E. transform-set
【多选题】
When using the Adaptive Security Device Manager（ASDM), which two options are available to add a new root certificate？___
A. Install from SFTP server
B. Usehttps
C. Install from a file
D. Use LDAP
E. Use SCEP
【多选题】
Which two SNMPv3 services support its capabilities as a secure networ k manage protocol？ ___
A. access control
B. the shared secret key
C. authentication
D. authorization
E. accounting
【多选题】
Which two statements about routed firewall mode are true ？___
A. The firewall acts as a routed hop in the network
B. This mode conceals the presence of the firewall
C. The firewall requires a unique iP address for each interface
D. This mode allows the firewall to be added to an existing networ k with minimal additional configuration By default， this mode permits most traffic to pass throug
【多选题】
Which two statements describe DHCP spoofing attacks？___
A. They are used to perform man-in- the-middle attacks
B. They can access most network devices
C. They can modify the flow of traffic in transit. LNGKAIG
D. They protect the identity of ti attacker by masking the DHCP address
E. They can physically modify the network gateway
【多选题】
Which two types of VLANs using PVLANs are valid？___
A. isolated
B. promiscuous
C. backup
D. secondary
E. community
【多选题】
What are two limitations of the self-zone policies on a zone-based firewall？___
A. They are unable to block Https traffic
B. They restrict SNMP traffic.
C. They are unable to support Https traffic
D. They are unable to implement application inspection
E. They are unable to perform rate limiting
【多选题】
Which two descriptions of TACACS+ are true？ ___
A. The TACACS+ header is unencrypted
B. It combines a uthentication and authorization
C. It uses TCP as its transport protocol
D. Only the password is encrypted.
E. It uses UDP as its transport protocol.
【多选题】
Which two actions does an IPS perform？ ___
A. it spans the traffic
B. it reflects the traffic back to the sender
C. it encrypts the traffic
D. it terminates the user session or connection of the attacker
E. it reconfigures a device to block the traffic
【多选题】
In which form of fraud does an attacker try to learn information such as login credenti account information by ma squerading as a reputable entity or person in email， IM or communication channels ?___
A. phishing
B. Smurfit
C. Hacking
D. Identity Spoofing
【多选题】
Which two ESA services are available for incoming and outgoing mails ？___
A. anti-DoS
B. reputation filter
C. antispam
D. content filter
E. DLP
【多选题】
What are two reasons to recommend SNMPv 3 over SNMPv2？___
A. SNMPv3 is secure because you can configure authe ntication and privacy
B. SNMPv3 is insecure because it send in formation in clear text
C. SNMPv2 is insecure because it send information in clear text
D. SNMPv3 is a Cisco proprietary protocol
E. SNMPv2 is secure because you can configure authentication and privacy
