【单选题】
(71107)交流电路中的视在功率用符号( )表示。(1.0分)___
A. P
B. Q
C. S
D. L
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答案
C
解析
暂无解析
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【单选题】
(71108)把两个或两个以上的电容器首尾相连的连接方式,叫电容器的( )。(1.0分)___
A. 串联
B. 并联
C. 串并联
D. 混联
【单选题】
(71109)电容器并联,各并联电容器的等效电容器所带电量等于各个电容器的电量( )。(1.0分)___
A. 之和
B. 之差
C. 之积
D. 之商
【单选题】
(71110)电路中形成电流的必要条件是有( )存在,而且电路必须闭合。(1.0分)___
A. 电阻
B. 电流
C. 电源
D. 用电器
【单选题】
(71111)电路通常有通路、开路、( )三种状态。(1.0分)___
A. 短路
B. 断路
C. 直流电路
D. 交流电路
【单选题】
(71112)荧光灯晶体管逆变器在工作中损坏的原因,多数是由于( )被较高的电压击穿的缘故。(1.0分)___
A. 电容器
B. 电感线圈
C. 晶体管
D. 晶闸管
【单选题】
(71113)电路中两点间的电压值高,则( )。(1.0分)___
A. 这两点的电位都高
B. 这两点的电位差大
C. 这两点的电位都大于零
D. 这两点的电位不确定
【单选题】
(71114)某导体在5 min内均匀通过的电荷量为4.5 C,则导体中的电流是( )。(1.0分)___
A. 0.015 mA
B. 1.5 mA
C. 0.15 mA
D. 15 mA
【单选题】
(71115)电流通过导体使导体发热的现象叫( )。[231110206](1.0分)___
A. 热传递
B. 电流的发热的现象
C. 电流的热效应
D. 热能
【单选题】
(71116).通常,当温度升高时,金属材料的电阻( )。[221110223](1.0分)___
A. 增大
B. 减小
C. 不变
D. 与温度无关
【单选题】
(71117)有一个电压表,其内阻为1.8 k ,现在要将它的量程扩大为原来的10倍,则应( )。[211110218](1.0分)___
A. 用18 k 的电阻与电压表串联
B. 用180 k 的电阻与电压表并联
C. 用16.2 k 的电阻与电压表串联
D. 用180 k 的电阻与电压表串联
【单选题】
(71118)KZS/M-Ⅰ型轴报器测量温度范围为( )。[322110214](1.0分)___
A. -45~125 ℃
B. -15~105 ℃
C. -65~135 ℃
D. -45~145 ℃
【单选题】
(71119)造成交流接触器线圈过热而烧毁的原因是( )。[213110223](1.0分)___
A. 电压过高
B. 电压过低
C. 线圈短路
D. ABC三项都对
【单选题】
(71120)接触器触头重新更换后应调整( )。[213110806](1.0分)___
A. 压力、开距、超程
B. 压力
C. 压力、开距
D. 超程
【单选题】
(71121)将一根均匀的电阻丝接在电源上,通过的电流为10A,再把这根电阻丝对折后,仍接在该电源上,这时通过的电流是( )。[212110217](1.0分)___
A. 40 A
B. 20 A
C. 10 A
D. 2.5 A
【单选题】
(71122)电源电动势是2 V,内电阻是0.1 ,当外电路断路时,电路中的电流和端电压分别为( )。[211110217](1.0分)___
A. 0,2 V
B. 20A,2 V
C. 20A,0
D. 0,0
【单选题】
(71123)电源电动势是2 V,内电阻是0.1 ,当外电路短路时,电路中的电流和端电压分别为( )。[212110217](1.0分)___
A. 20A,2 V
B. 20A,0
C. 0,20 V
D. 0,0
【单选题】
(71124).在全电路中,当负载电阻增大,端电压将( )。[222110217](1.0分)___
A. 降低
B. 升高
C. 不变
D. 不确定
【单选题】
(71125)晶体管逆变器通常用( )作变压器铁芯材料。(1.0分)___
A. 铁淦氧
B. 坡莫合金
C. 硅钢片
D. 钡铁氧体
【单选题】
(71126)在全电路中,当负载短路时,电源内压降( )。(1.0分)___
A. 为零
B. 等于电源电动势
C. 等于端电压
D. 不确定
【单选题】
(71127)BY-2型逆变器过流保护装置的主要元件为( )。(1.0分)___
A. 整流二极管
B. 晶闸管
C. 三极管
D. 镇流器
【单选题】
(71128)负有事故主要责任的,承担损失费用的( )以上。(1.0分)___
A. 80%
B. 50%
C. 30%
D. 20%
【单选题】
(71129)在轴温监测与报警装置中,目前采用具有( )的半导体PN结作为温度传感器。(1.0分)___
A. 低阻值
B. 中阻值
C. 高阻抗
D. 不能确定
【单选题】
(71130)事故受伤人员经救治无效,在( )内死亡,按死亡统计。(1.0分)___
A. 2日
B. 5日
C. 7日
D. 10日
【单选题】
(71131)KP-2A型控制箱中的主整流器采用( )整流电路。(1.0分)___
A. 三相桥式
B. 单相桥式
C. 二倍压
D. 三相可控
【单选题】
(71132)对一导体而言,R=U/I的物理意义是( )(1.0分)___
A. 导体两端电压越大,则电阻越大
B. 导体中电流越小,则电阻越大
C. 导体的电阻等于导体两端电压与通过导体的电流的比值
D. 没有实际意义
【单选题】
(71133)“安监报2”须保管( )。(1.0分)___
A. 1年
B. 2年
C. 3年
D. 4年
【单选题】
(71134)KSL-Ⅲ型系列电开水炉,其电热管的绝缘电阻应大于( )。(1.0分)___
A. 2 M
B. 0.5 M
C. 4 M
D. 1 M
【单选题】
(71135)电容器在充电瞬间相当于( )。(1.0分)___
A. 短路
B. 开路
C. 断路
D. 通路
【单选题】
(71136)干扰、阻碍事故调查处理的,对单位,由铁道部或安全监管办处4万元以上( )以下的罚款。(1.0分)___
A. 5万元
B. 10万元
C. 20万元
D. 30万元
【单选题】
(71137)统型应急电源箱整流器输入电源为( )。(1.0分)___
A. 单相交流220 V
B. 三相交流450 V
C. 三相交流380 V
D. 直流600 V
【单选题】
(71138)电容器的结构繁多,按其结构分为固定电容器、可变电容器和( )三种。(1.0分)___
A. 微调电容器
B. 电解电容器
C. 存储电容器
D. 整流电容器
【单选题】
(71139)外墙、顶板需全部分解,并须更换铁立柱达( )的符合客车报废条件。(1.0分)___
A. 1/3
B. 2/3
C. 1/4
D. 3/4
【单选题】
(71140)统型应急电源箱充电机输入电压为( )。(1.0分)___
A. 三相交流380 V
B. 单相交流220 V
C. 三相交流450 V
D. 直流110 V
【单选题】
(71141)各段熔断器的配合中,电路上一级的熔断时间应为下一级熔断器的( )以上。(1.0分)___
A. 1倍
B. 2倍
C. 3倍
D. 4倍
【单选题】
(71142)旅客列车入库进行技术检查作业的时间每次不得少于( )。(1.0分)___
A. 2 h
B. 4 h
C. 6 h
D. 8 h
【单选题】
(71143)统型应急电源箱充电机主电路为( )桥式整流器。(1.0分)___
A. 单相半控
B. 单相全控
C. 三相
D. 单相
【单选题】
(71144)电源电动势的瞬时值表达式e =Emsin t中的 通常称为( )(1.0分)___
A. 角度
B. 速度
C. 角频率
D. 频率
【单选题】
(71145)两个正弦量相同,说明两个正弦量的相位差为( )。(1.0分)___
A. 180°
B. 90°
C. 270°
D. 0°
【单选题】
(71146)KP-2A型控制箱是以( )作为感应子发电机自励恒压的主要控制元件。(1.0分)___
A. 晶闸管
B. 三极管
C. 稳压二极管
D. 单结晶体管
【单选题】
(71147)标记速度为160 km/h的客车运行( )(或距上次各级修程不超过1年)实施A1级检修。(1.0分)___
A. 10万km±2万km
B. 20万km±2万km
C. 30万km±2万km
D. 40万km±2万km
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【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
【多选题】
Which two actions can a zone- based firewall apply to a packet as it transits a zone pair?___
A. drop
B. inspect
C. queue
D. quarantine
【单选题】
Which security principle has been violated if data is altered in an unauthorized manner?___
A. accountability
B. confidentiality
C. availability
D. integrity
【单选题】
Which IKE Phase 1 parameter can you use to require the site-to-site VPN to use a pre-shared ?___
A. encryption
B. authentication
C. group
【单选题】
Which command successfully creates an administrative user with a password of "cisco"on a Cisco router?___
A. username Operator privilege 7 password cisco
B. username Operator privilege 1 password cisco
C. username Operator privilege 15 password cisco
D. username Operator password cisco privilege 15
【单选题】
Which EAP method authenticates a client against Active Directory without the use of client-side 802.1X certificates?___
A. EAP-TLS
B. EAP-MSCHAPv2
C. EAP-PEAP
D.
E. AP-GTC
【单选题】
What is a limitation of network-based IPS?___
A. It must be in dividually configured to support every operating system on the network.
B. It is most effective at the in dividual host level
C. It is unable to monitor attacks across the entire netw ork
D. Large installations require numerous sensors to fully protect the network
【单选题】
When would you configure the ip dhcp snooping trust command on a sw itch?___
A. when the switch is connected to a DHCP server
B. when the switch is working in an edge capacit
C. when the switch is connected to a client system
D. when the switch is serving as an aggregator
【单选题】
How does the 802. 1x supplicant communicate with the authentication server?___
A. The supplicant creates EAP packets and sends them to the authenticator, which encapsulates them into RADIUS and forwards them to the authentication server.
B. The supplicant creates RADIUS packets and sends them to the authe nticator, which encapsulates the m into EAP and forwards them to the a uthentication server.
C. The supplicant creates RADIUS packets and sends them to the authenticator, which translates them into eap and forwards them to the a ut hentication server
D. The supplicant creates
E. AP packets and sends them to the authe nticator, which translates them into radius and forwards them to the authentication server.
【单选题】
Which command do you enter to verify the phase I status of a VPN connection?___
A. sh crypto se ssion
B. debug crypto isakmp
C. sh crypto isakmp sa
D. sh crypto ipsec sa
【单选题】
Refer to the exhibit. what is the e ffect of the given configuration?___
A. It enables authentication,
B. It prevents keychain authentication.
C. The two routers receive normal updates from one another.
D. The two device s are able to pass the message digest to one another.
【单选题】
Which command can you enter to configure OSPF to use hashing to authenticate routing updates?___
A. ip ospf aut hentication message-digest
B. neighbor 192 168.0 112 cost md5
C. ip ospf priority 1
D. ip ospf aut hentication-key
【单选题】
Which command can you enter to verify the status of Cisco lOS Resilient Configuration on a Cisco router?___
A. show secure bootset
B. secure boot-image
C. show binary file
D. ure boot-config
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A user on your network inadvertently activates a botnet program that was received as an emai attachment. Which type of mechanism does Cisco Firepower use to detect and block only the botnet attack?___
A. network-based access control rule
B. reputation-based
C. user-ba sed access control rule
D. botnet traffic filter
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What does the policy map do in CoPP?___
A. defines service parameters
B. defines packet selection parameters
C. defines the packet filter
D. define s the action to be performed
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How is management traffic isolated on a Cisco ASR 1002?___
A. Traffic isolation is done on the vlan level
B. There is no management traffic isolation on a Cisco ASR 1002
C. Traffic is isolated based upon how you configure routing on the device
D. The management interface is configured in a special vRF that provides traffic isolation from the default routing table
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Which statement about NaT table evaluation in the asa is true?___
A. After-auto NAT polices are appl d first
B. Manual NAT policies are applied first
C. the asa uses the most specific match
D. Auto NAT policies are applied first
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Which information can you display by executing the show crypto ipsec sa command?___
A. ISAKMP SAs that are established between two peers
B. recent changes to the IP address of a peer router
C. proxy infor mation for the connection between two peers
D. IPsec SAs established between two peers
【单选题】
How can you prevent NAT rules from sending traffic to incorrect interfaces?___
A. Assign the output interface in the NAT statement
B. Add the no-proxy-arp command to the nat line.
C. Configure twice NAT instead o bject NAT. 5
D. Use packet-tracer rules to reroute misrouted NAT entries.
【单选题】
What term can be defined as the securing, control, and identification of digital data?___
A. cryptography
B. crypto key
C. cryptoanalysis
D. cryptology
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Which feature in the dNS security module provide on and off network DNS protection?___
A. Data Loss Prevention
B. Umbrella
C. Real-time sandboxing
D. Layer-4 monitoring
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Which a dverse consequence can occur on a network without BPDu guard ?___
A. The olde st switch can be elected as the root bridge
B. Unauthorized switches that are connected to the network can cause spanning-tree loops
C.
D. ouble tagging can cause the switches to experience CAM table overload.
【单选题】
What configuration is required for multitenancy ?___
A. shared infrastructure
B. multiple carriers
C. co-located resources
D. multiple separate zones
【单选题】
Why does ISE require its own certificate issued by a trusted CA?___
A. ISEs certificate allows guest devices to validate it as a trusted network device
B. It generates certificates for guest devices ba sed on its own certificate
C. It requests certificates for guest devices from the Ca server based on its own certificate.
D. ISE's certificate allows it to join the network security framework
【单选题】
which attack involves large numbers of ICMP packets with a spoofed source IP address?___
A. smurf attack
B. Teardrop attack
C. Nuke attack
D. SYN Flood attack
【单选题】
Which statement about interface and global access rules is true?___
A. Interface access rules are processed before global access rules.
B. Global access rules apply only to outbound traffic, but interface access rules can be applied in either direction
C. The implicit allow is proce ssed after both the global and interface access rules
D. If an interface access rule is applied, the global access rule is ignored
【单选题】
Which type of malicious software can create a back-door into a device or network?___
A. bot
B. worm
C. virus
D. Trojan
【单选题】
Which security term refers to the like lihood that a weakness will be exploited to cause damage to an asset?___
A. threat
B. risk
C. countermeasure
D. vulnerability
【单选题】
Which IPS detection method examines network traffic for preconfigured patterns?___
A. signature-based detection
B. honey-pot detection
C. anomaly-based detection
D. policy-based detection
【单选题】
What is an advantage of split tunneling ?___
A. It allows users with a VpN connection to a corporate network to access the internet with sending traffic across the cor porate network.
B. It allows users with a vpn connection to a corporate network to access the internet by using the vPN for security.
C. It protects traffic on the private network from users on the public network
D. It enables the VPN server to filter traffic more efficiently
【单选题】
Which IDS/IPS state misidentifies acceptable behavior as an attack ?___
A. false negative
B. true positive NEKA G
C. true negative
D. false positive
【单选题】
What is the maximum num ber of methods that a single method list can contain?___
A. 4
B. 3
C. 2
D. 5
【单选题】
Which command enables authentication at the oSPFv2 routing process level?___
A. ip ospf authentication message-digest
B. area 0 authentication message-digest
C. ip ospf message-digest-key 1 mds Cisco
D. area 0 authentication ipsec spi 500 md5 1234567890ABCDEF1234567890ABCDEF
【单选题】
Which type of firewall monitors a nd protects a specific system?___
A. firewall
B. application firewall
C. stateless firewall wvp
D. personal firewall