【单选题】
22所谓2P的继电器,代表什么意思?___
A. 只有2个接点
B. 两相的负载
C. 两组电源
D. 2组c接点
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答案
D
解析
暂无解析
相关试题
【单选题】
23共阳极七段数码管显示器的驱动信号有何特色?___
A. 低电平点亮
B. 低电平不亮
C. 高电平点亮
D. 以上皆非
【单选题】
24在8×51的程序里,若要将某个输入/输出端口设置成输入功能,应如何处理?___
A. 先输出高电平到该输入/输出端口
B. 先输出低电平到该输入/输出端口
C. 先读取该输入/输出端口的状态
D. 先保存该输入/输出端口的状态
【单选题】
8×51提供几个外部中断和定时器/计数器中断?___
A. 2,2
B. 3,6
C. 2,3
D. 3,7
【单选题】
8×51的IP缓存器的功能如何?___
A. 设置中断优先级
B. 启动中断功能
C. 设置中断触发信号
D. 定义CPU的网址
【单选题】
28若要让采用低电平触发,则应如何设置?___
A. EX0=0
B. EX0=1
C. IT0=0
D. IT0=1
【单选题】
29在Keil µVision3里进行调试/仿真时,在哪里操作才能触动程序中断?___
A. 在Interrupt System
B. 在Cotorl Box对话框里
C. 直接单击魔术棒按钮即可
D. 直接按0键
【单选题】
30在8×51所提供的中断功能里,下列哪个优先级比较高?___
A. T1
B. RI/TI
C. T0
D. INT0
【单选题】
31在TCON缓存里,IE1的功能是什么?___
A. 触发 IE1中断
B. 指示IE1中断的标志
C. 提高IE1优先等级
D. 取消IE1中断
【单选题】
32在Keil C里,中断子程序与函数又何不同?___
A. 中断子程序不必声明
B. 函数不必声明
C. 中断子程序必须有形式参数
D. 中断子程序一定会有返回值
【单选题】
33若要同时启用INT0及INT1中断功能,则应如何设置?___
A. TCON=0×81
B. IE=0×85
C. IP=0×83
D. IE=0×03
【单选题】
35在8×51的Timer里,若使用Mode 0,其最大计数值为多少个机器周期?___
A. 65636
B. 8192
C. 1024
D. 256
【单选题】
36在12MHz的8×51系统里,哪一种方式一次可定时5ms?___
A. Mode 0及Mode 1
B. Mode 1及Mode 2
C. Mode 2及Mode 3
D. Mode3及Mode 1
【单选题】
37若要让Timer作为外部计数只用,应如何设置?___
A. Gate=0
B. Gate=1
C. C/=0
D. C/=1
【单选题】
39下列哪个不是8×51所提供的省电方式?___
A. PD方式
B. IDL方式
C. LP方式
D. 待机方式
【单选题】
89S51的看门狗有何作用?___
A. 重复执行程序
B. 找回遗失数据
C. 复位系统
D. 防止中毒
【单选题】
41若要启用WDT,则应依次填入WDTRST寄存器哪些数据?___
A. 0xe1、0xe2
B. 0xe1、0x1e
C. 0x1e、0xe1
D. 0x10、0x01
【单选题】
8×51的定时器,在下列哪种方式下具有自动加载功能?___
A. Mode0
B. Mode1
C. Mode2
D. Mode3
【单选题】
45下列哪种AD转换器的转换速度比较快?___
A. 双斜率型AD转换器
B. 比较型AD转换器
C. 连续计数式AD转换器
D. 逐渐接近式AD转换器
【单选题】
46下列哪种AD转换器的精密度比较高?___
A. 双斜率型AD转换器
B. 比较型AD转换器
C. 连续计数式AD转换器
D. 逐步逼近式AD转换器
【单选题】
47对于8×8 LED点阵而言,其中的LED个数及引脚各为多少?___
A. 64、16
B. 16、16
C. 64、12
D. 32、12
【单选题】
48在共阳极型8×8 LED点阵里,其阳极如何连接?___
A. 各行阳极连接到行引脚
B. 各列阳极连接到列引脚
C. 各行阳极连接到列引脚
D. 各列阳极连接到行引脚
【单选题】
49在共阳极型8×8 LED点阵里,其阴极如何连接?___
A. 各行阴极连接到行引脚
B. 各列阴极连接到列引脚
C. 各行阴极连接到列引脚
D. 各列阴极连接到行引脚
【单选题】
50双色8×8 LED点阵的列引脚与行引脚各位多少?___
A. 12、12
B. 8、16
C. 16、8
D. 24、8
【单选题】
___的方向规定由高电位点指向低电位点。
A. 电压
B. 电流
C. 能量
D. 电能
【单选题】
三相电动势到达最大的顺序是不同的,这种达到最大值的先后次序,称三相电源的相序,相序为U-V-W-U,称为___。
A. 正序
B. 负序
C. 逆序
D. 相序
【单选题】
电路的作用是实现能量的传输和转换、信号的___和处理。
A. 连接
B. 传输
C. 控制
D. 传递
【单选题】
电阻器反映导体对电流起阻碍作用的大小,简称___。
A. 电动势
B. 功率
C. 电阻率
D. 电阻
【单选题】
___反映了在不含电源的一段电路中,电流与这段电路两端的电压及电阻的关系。
A. 欧姆定律
B. 楞次定律
C. 部分电路欧姆定律
D. 全欧姆定律
【单选题】
并联电路中的总电流等于各电阻中的___。
A. 倒数之和
B. 相等
C. 电流之和
D. 分配的电流与各电阻值成正比
【单选题】
串联电路中流过每个电阻的电流都___。
A. 电流之和
B. 相等
C. 等于各电阻流过的电流之和
D. 分配的电流与各电阻值成正比
【单选题】
___的一端连在电路中的一点,另一端也同时连在另一点,使每个电阻两端都承受相同的电压,这种联结方式叫电阻的并联。
A. 两个相同电阻
B. 一大一小电阻
C. 几个相同大小的电阻
D. 几个电阻
【单选题】
___的电阻首尾依次相连,中间无分支的联结方式叫电阻的串联。
A. 两个或两个以上
B. 两个
C. 两个以上
D. 一个或一个以上
【单选题】
电流流过负载时,负载将电能转换成___。
A. 机械能
B. 热能
C. 光能
D. 其他形式的能
【单选题】
电功的数学表达式不正确的是___。
A. W=Ut/R2t
B. W=UIt
C. W=U2t/Rt
D. W=I2Rt
【单选题】
测量电压时,电压表应与被测电路___。
A. 并联
B. 串联
C. 正接
D. 反接
【单选题】
测量电流时,万用表的接线方法与直流电流表一样,应把万用表___在电路中。测量直流电压时,应把万用表与被测电路并联。
A. 串联
B. 并联
C. 正接
D. 反接
【单选题】
串联电路中各电阻两端电压的关系是___。
A. 各电阻两端电压相等
B. 阻值越小两端电压越高
C. 阻值越大两端电压越高
【单选题】
确定正弦量的三要素为 ___。
A. 相位、初相位、相位差
B. 最大值、频率、初相角
C. 周期、频率、角频率
【单选题】
纯电容元件在电路中___电能。
A. 储存
B. 分配
C. 消耗
【单选题】
当电压为5V时,导体的电阻值为5欧,那么当电阻两端电压为2V时,电阻值为___欧。
A. 10
B. 5
C. 2
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Which quantifiable item should you consider when you organization adopts new technologies?___
A. exploits
B. vulnerability
C. threat
D. Risk
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Referencing the ClA model, in which scenario is a hash- only function most appropriate ?___
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B. securing real-time traffic
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Which ports must be open between a aaa server and a microsoft server to permit Active Directory authentications?___
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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
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Which type of attack can exploit design flaws in the implementation of an application without___
A. DHCP starvation attacks
B. low-rate dos attacks
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D. application DDoS flood attacks
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【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
【多选题】
Which two statements regarding the aSA VPN configurations are correct?___
A. The asa has a certificate issued by an external certificate authority associated to the ASDM TrustPoint1
B. The Default WEBVPNGroup Connection Profile is using the aaa with RADIUS server method
C. The Inside-srvbook mark references the https://192.168.1.2url
D. Only Clientless SSL VPN access is allowed with the Sales group policy
E. Any Connect, IPSec IKEv1, and IPSec IKEv2 VPN access is enabled on the outside interface
F. The Inside -SRV bookmark has not been applied to the Sales group policy
【多选题】
Which three ESP fields can be encrypted during transmission?___
A. Security Parameter Index
B. Sequence Number
C. MAC Address
D. Padding
E. Pad length
F. Next Header
【多选题】
.Which three statements de scribe DHCP spoofing attacks?___
A. They can modify traffic in transit.
B. They are used to perform man- in-the-middle attacks
C. They use ARP poisoning
D. They can access most network devices
E. They protect the ide ntity of the attacker by masking the DHCP address.
F. They are can physically modify the network gateway.
【多选题】
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
【多选题】
In which two situations should you use in band management? ___
A. when the control plane fails to respond
B. when you require administrator access from multiple locations
C. when you require ROMMON access.
D. where a network device fails to forward packets
E. when multiple ma nagement applications need concument access to the device.
【多选题】
Which two features are supported in a VRF-aware softwar infrastructure before VRF-lite?___
A. multicast
B. fair queuing
C. WCCP
D.
E. IGRP
【多选题】
.Which loS command do you enter to test authentication again a AAA server?___
A. dialer aaa suffix <suffix> password <password>
B. ppp authentication chap pap test
C. test aaa-server authentication dialer group user name <user> password <password>
D. aaa authentication enable default test group tacases
【多选题】
Which two statements about the self zone on a cisco Xone based policy firewall are true?___
A. Multiple interfaces can be assigned to the self zone
B. it supports stateful inspections for multicast traffic
C. zone pairs that include the self zone apply to traffic transiting the device.
D. it can be either the source zone or the destination zone
E. traffic entering the self zone must match a rule
【多选题】
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
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【单选题】
Which type of firewall can server as the interme diary between a client and a server ?___
A. Stateless firewall
B. application firewall
C. proxy firewall
D. personal firewall
【单选题】
What is the highest security level that can be configured for an interface on an ASA?___
A. 0
B. 50
C. 10
D. 200
【单选题】
Which term refers to the electromagnetic interference that can radiate from network cables?___
A. Gaussian distributions
B. Doppler waves
C. emanations
D. multimode distortion
【单选题】
How does a zone pair handle traffic if the policy de fination of the zone pair is missing?___
A. It inspects all traffic.
B. It drops all traffic.
C. It permits all traffic wihtout logging
D. It permits and logs all traffic
【单选题】
default how does a zone based firewall handle traffic to add from the self zone?___
A. It permits all traffic without inspection
B. It inspects all traffic to determine how it is handled
C. It permits all traffic after inspection
D. It frops all traffic
【单选题】
Which command should beused to ena ble AAA Authentication to determine if a user can access the privilege command level?___
A. aaa authentication enable local
B. aaa authentication enable level=
C. aaa authentication enable method de fault
D. aaa authentication enable defa ult local
【单选题】
On an ASA, the policy indicates that traffic should not be translated is often referred to as which of the following?___
A. NAT zero
B. NAT forward
C. NAT nul
D. NAT allow
【单选题】
Which protocol offers data Integrity encryption, authentication, and anti-replay functions for IPSec VPN?___
A. ESP protocol
B. IKEv3 Protocol
C. AH protoco
D. IKEv1 Protocol
【单选题】
Which component offers a variety of security Solution, including firwall, IF Antivirus and antiphishing features?___
A. Cisco loS router
B. Cisco ASA 5500 Ser ies security appliance
C. Cisco ASA 5500 X series Next Gen Security appliance
D. Cisco 4200 series IPS appliance
【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