【单选题】
短路电流通过线路,要产生很大的电流降,使系统的电流水平骤降,引起电动机转速突然下降,甚至停转,严重影响电气设备的正常运行。___
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相关试题
【单选题】
10KV及以下三相供电的,电压允许偏差为额定电压的为±10%。___
【单选题】
良好的摇表,在摇表两连接线(LE)短接时,摇动手柄,指针应在“0”处。___
【单选题】
三相电度表应按正相序接线,经电流互感器接线者极性错误也不影响测量结果。___
【单选题】
在电阻并联的电路中,电路总电阻等于各并联电阻之和。___
【单选题】
配电所运行管理条例中规定两票制度必须严格执行,其所指的两票是倒闸操作票和交接班当值票。___
【单选题】
用户变电站或配电室进行并路倒闸时,不应自行停用进线保护。___
【单选题】
交流真空接触器-熔断器组合电器,的使用空间。___
【单选题】
RN2型高压熔断器可适用于作___的保护。
【单选题】
断路器的额定电流是指在规定环境温度下,断路器长期允许通过的___。
A. 最小工作电流
B. 短路电流
C. 最大工作电流
【单选题】
为保证继电保护动作的选择性,一般上下级保护的时限差取___。
A. 0.1-0.3s
B. 0.3-0.7s
C. 1s
【单选题】
下列()属于电气设备不正常运行状态。___
【单选题】
___是指那些绝缘强度能长期承受设备的工作电压,并且在该电压等级产生内部过电压时能保证工作人员安全的用具。
A. 绝缘安全用具
B. 一般防护安全用具
C. 基本安全用具
【单选题】
电力线路的导线是用来___。
A. 输送电能分配电能
B. 传导电流,输送电能
C. 输送电能消耗电能
【单选题】
在中性点接地的电力系统中,以___的短路故障最多,约占全部故障的90%。
【单选题】
在电阻并联的电路中,电路的端电压等于___。
A. 各并联支路端电压的平均值
B. 各并联支路的端电压
C. 各并联支路的端电压之和
【单选题】
为防止直接雷击架空线路,一般多采用___。
【单选题】
运行值班人员在室内进行巡回检查,如高压设备发生接地时,不得接近故障点___以内。
【单选题】
手车式开关柜,小车已推入,开关断开,称之为___。
【单选题】
弹簧储能操动机构的加热器只在断路器检修时使用。___
【单选题】
电容器正常运行时,可在.倍额定电压下长期运行。___
【单选题】
电力线路过电流保护的动作电流按躲过最大负荷电流整定。___
【单选题】
三相一次或二次重合闸属于110KV及以下线路保护测控装置在测控方面的主要功能。___
【单选题】
在高压带电设备上,辅助安全工具可作为基本安全用具使用。___
【单选题】
移动式电气设备的性能与现场使用条件无关。___
【单选题】
S11-160/10表示三相油浸自冷式,双绕组无励磁调压,额定容量160KVA,低压侧绕组额定电压为10KV电力变压器。___
【单选题】
运行中的电压互感器出现瓷套管破裂严重放电,可继续运行。___
【单选题】
变压器运行巡视应检查储油柜和充油绝缘套管内油面的高度和封闭处有无渗漏油现象,以及油标管内的油色。___
【单选题】
变压器是一种静止的电气设备,它利用电磁感应原理将一种电压等级的交流电转变成异频率的另一种电压等级的交流电。___
【单选题】
电力电缆的基本结构由线芯(导体)绝缘层屏蔽层和接地层四部分组成。___
【单选题】
导线允许载流量取决于其容许工作温度。___
【单选题】
输电线路电压一般在110KV及以上,220KV以上的也称超高压输电线路。___
【单选题】
低压配电线路的电压为10KV及以下。___
【单选题】
从发电厂发电机开始一直到变电设备为止,这一整体称为电力系统。___
【单选题】
变电所运行中,如交接班时发生事故,应由接班人员负责处理。___
【单选题】
在二次接线回路上工作,无需将高压设备停电时应使用第一种工作票。___
【单选题】
绝缘棒每个月要进行一次绝缘试验,保证绝缘棒完好___
【单选题】
有填料高压熔断器利用___原理灭弧。
A. 利用电弧与固体介质接触加速灭弧
B. 窄缝灭弧
C. 将电弧分割成多个短电弧
【单选题】
目前使用的某些断路器的检修年限可达___以上。
【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
推荐试题
【单选题】
Within an 802. 1x-enabled network with the auth Fail feature configured， when does a switch port get placed into a restricted VLAN？___
A. When a conected client fails to authenticate after a certain number of attempts.
B. if a connected client does not support 802. 1x
C. when AAA new-model is ena bled
D. after a connected client exceeds a specified idle time
E. when 802. 1x is not globally enabled on the Cisco Catalyst switch
【单选题】
Which type of attack does a proxy firewall protect against ？___
A. cross-site scripting attack
B. worm traffic
C. port scanning
D. DDoS attacks
【单选题】
When an administrator initiates a device wipe command from the ISE， what is the immediate effect？___
A. It requests the administrator to choose between erasing all device data or only managed corporate data.
B. It requests the administrator to enter the device pin or password before proceeding with the operation
C. It notifies the device user and proceeds with the erase operation
D. It immediately erases all data on the device
【单选题】
What is a valid implicit permit rule for traffic that is traversing the ASa firewall？___
A. ARPs in both directions are permitted in transparent mode only
B. Unicast IPv4 traffic from a higher security interface to a lower security interface is permittee in routed mode only.
C. Unicast IPv6 traffic from a higher security interface to a lower security interface is permitted in transparent mode only.
D. Only BPDUs from a higher security interface to a lower secur ity interface are permitted in transparent mode.
E. Only BPDUs from a higher security interface to a lower secur ity interface are permitted in routed mode
【单选题】
A specific URL has been identified as containing malware. What action can you take to block users from accidentally visiting the URl and becoming infected with malware ？___
A. Enable URL filtering on the perimeter router and add the URls you want to block to the router's local URL list
B. Enable URL filtering on the perimeter firewall and add the URls you want to allow to the router's local URL list.
C. Enable URL filtering on the perimeter router and add the URls you want to allow to the firewall's local URL list
D. Create a blacklist that contains the URl you want to block and activate the blacklist on the perimeter rout
E. Create a whitelist that contains the URLs you want to allow and activate the whitelist on the perimeter router.
【单选题】
How does PEAP protect the EAP exchange ？___
A. It encrypts the exchange using the server certificate
B. It encrypts the exchange using the client certificate
C. It validates the server-supplied certificate,and then encrypts the exchange using the client certificate
D. It validates the client-supplied certificate,and then encrypts the excha nge using the server certificate
【单选题】
Which feature of the Cisco Email Security Appliance can mitigate the impact of snowshoe spam and sophisticated phishing attacks？___
A. contextual analysis
B. holistic understanding of threats
C. graymail management and filtering
D. signature-based IPS
【单选题】
Refer to the exhibit【nat (inside,outside)dunamic interface】 Which translation technique does this configuration result in？___
A. DynamIc PAT
B. Dynamic NAT
C. Twice NAT
D. Static NAT
【单选题】
Refer to the exhibit which are repre sents the data center？___
【单选题】
While trouble shooting site-to-site VPN， you issued the show crypto isakmp sa command. What does the given output show？___
A. IKE Phase 1 main mode was created on 10.1.1.5， but it failed to negotiate with 10.10 10.2
B. IKE Phase 1 main mode has successfully negotiated between 10.1.1.5 and 10.10..
C. IKE Phase 1 aggressive mode was created on 10.1.1.5， but it failed to negotiate with
【单选题】
Refer to the exhibit All ports on switch 1 have a primary vLan of 300 Which devices can host 1 reach？___
A. host 2
B. server
C. host 4
D. other devices within VLAN303
【单选题】
Which option is the cloud-based security service from Cisco the provides URL filtering， web browsing content security， and roaming user protection？___
A. Cloud Web service
B. Cloud Advanced Malware Protection
C. Cloud We b Security
D. Cloud Web Protection
【单选题】
How can you detect a false negative on an IPS？___
A. View the alert on the ips
B. Review the ips log
C. Review the is console
D. Use a third- party system to perform penetration testing.
E. Use a third- party to audit the next generation firewall rules
【单选题】
If a switch port goes directly into a blocked state only when a superior BPDU is received， what mechanism must be in use？___
A. STP BPDU guard
B. Loop guard
C. EtherChannel guard
D. STP Root guard
【单选题】
what improvement does EAP-FASTv2 provide over EAP-FAST？ ___
A. It allows multiple credentials to be passed in a single EAP exchange.
B. It supports more secure encryption protocols
C. It allows faster authentication by using fewer packets.
D. It addresses security vulnerabilities found in the original protocol
【单选题】
When users login to the Client less Ssl Vpn using https://209.165.201.2/test ,which group policy will be applied？___
A. test
B. clientless
C. sales
D. DfitGrp Policy
E. Default RAGroup
F. Default WEB VPN
G. roup
【单选题】
Which user authentication method is used when users login to the Clientless SSLVPN portal using https://209.165.201.2/test？___
A. AAA with LOCAL database
B. AAA with RADIUS server
C. Certificate
D. :Both Certificate and aaa with LoCAL database
E. Both Certificate and AAA with RADIUS server
【单选题】
What' s the technology that you can use to prevent non malicious program to runin the computer that is disconnected from the network？___
A. Firewall
B. Sofware Antivirus
C. Network IPS
D. Host IPS
【单选题】
Which statement about the communication between interfaces on the same security level is true？___
A. Interfaces on the same security level require additional configuration to permit interinterface communication
B. Configuring interfaces on the same security level can cause asymmetric routing
C. All traffic is allowed by default between interfaces on the same security level
D. You can configure only one interface on a n individual security level
【单选题】
Which product can be used to provide application layer protection for tcp port 25 traffic？___
A. ESA
B. CWS
C. WSA
D. ASA
【单选题】
which iPS mode is less secure than other options but allows optimal network through put ?___
A. inline mode
B. inline-bypass mode
C. transparent mode
D. Promiscuous mode
【单选题】
Which feature of the Cisco Email security Appliance can mitigate the impact of snowshoe spam and sophisticated phishing attack？___
A. reputation based filtering
B. signature based IPS
C. contextual analysis
D. graymail management and filtering
【单选题】
Which type of social-engineering attack uses normal tele phone service as the attack vector？___
A. smishing
B. dialing
C. phishing
D. vishing
【单选题】
Which quantifiable item should you consider when you organization adopts new technologies？___
A. exploits
B. vulnerability
C. threat
D. Risk
【单选题】
Referencing the ClA model， in which scenario is a hash- only function most appropriate ？___
A. securing data at rest
B. securing real-time traffic
C. securing data in files
D. securing wireless transmissions
【单选题】
Which ports must be open between a aaa server and a microsoft server to permit Active Directory authentications？___
A. 445 and 389
B. 888 and 3389
C. 636 and 4445
D. 363 and 983
【单选题】
Refer to the exhibit for which reason is the tunnel unable to pass traffic___
A. the tunnel is failing to receive traffic from the remote peer
B. the local peer is unable to encrypt the traffic
C. the ip address of the remote peer is incorrect
D. UDP port 500 is blocked
【单选题】
Which type of attack can exploit design flaws in the implementation of an application without___
A. DHCP starvation attacks
B. low-rate dos attacks
C. application DDos flood attacks
D. application DDoS flood attacks
E. volume-based DDoS attacks
【单选题】
How can you protect CDP from reconnaissance attacks？___
A. Enable dynamic ARP inspection on all untrusted ports.
B. Enable dot1x on all ports that are connected to other switches.
C.
D. isable CDP on ports connected to endpoints.
【单选题】
Which type of attack can exploit design flaws in the implementation of an application without ？___
A. DHCP starvation attacks
B. low-rate dos attacks
C. application DDos flood attacks
D. application DDoS flood attacks
E. volume-based DDoS attacks
【单选题】
Which option is a key security compone nt of and MDM deployment ？___
A. using network-specific installer packages
B. using an application tunnel by default
C. using self-signed certificates to validate the server
D. using MS-CHAPv2 as the primary
E. AP method
【单选题】
Which Firepower Management Center feature detects and block exploits and hack attempts？___
A. Content blocker
B. file control
C. intrusion prevention
D. advanced malware protection
【单选题】
hich description of the nonsecret numbers that are used to start a Diffie- Hellman exchange is ture？___
A. They are preconfigured prime integers.
B. They are large pseudorandom numbers.
C. They are very small numbers chosen from a table of known valuses
D. They are numeric values extracted from ha shed system hostnames
【多选题】
Which two characteristics of an application layer firewall are true？___
A. provides stateful firewal functionality
B. has low processor usage
C. provides protection for multiple applications
D. provides rever se proxy services
E. is immune to URL manipulation
【多选题】
Which two devices are components of the BYOD architectural framework？___
A. Nexus 7010 switch
B. Cisco 3945 Router
C. Identify Services Engine
D. Wireless Access oints
E. Prime Infrastructure
【多选题】
Which two actions can a zone based firewall take when looking at traffic？ ___
A. forward
B. inspect
C. drop
D. broadcast
E. filter
【多选题】
n which two situations should you use in-band management？___
A. when management applications need concurrent access to the device
B. when you require administrator access from multiple locations
C. when a network device fails to forward packets
D. when you require ROMMON access
E. when the control plane fails to respond
【多选题】
What are two ways to prevent eavesdropping when you perform device management tasks？___
A. Use an SSH connection.
B. Use SNMPv3
C. Use out-of-band management
D. Use SNMP
E. Use in-band management
【多选题】
Which two features are commonly used CoPP and CPPr to protect the control plane？ ___
A. QoS
B. traffic classification
C. access lists
D. policy maps
E. class maps
F. Cisco Express Forwarding
【多选题】
Which four tunne ling prot ocols are enabled in the Dfit GrpPolicy group policy ？___
A. Clientless SSL VPN
B. SSL VPN Client
C. PPTP
D. L2TP/IPsec
E. IPsec IKEv1
F. IPsec IKEv2
