CompTIA CompTIA Certifications FC0-U51 Questions & Answers

• Question 31:

  Which of the following protocols provides an encryption by using the Temporal Key Integrity Protocol (TKIP)?

  A. EAP

  B. WEP

  C. IPSec

  D. WPA

  Correct Answer: D

  Wi-fi Protected Access (WPA) is an interoperable security protocol for Wireless LAN (WLAN). For using WPA, encryption is required. WPA provides encryption by using Temporal Key Integrity Protocol (TKIP). TKIP uses a new encryption algorithm, which is stronger than WEP algorithm. 802.1x authentication is required in WPA. Answer option B is incorrect. Wired Equivalent Privacy (WEP) is a security protocol for wireless local area networks (WLANs). It has two components, authentication and encryption. It provides security, which is equivalent to wired networks, for wireless networks. WEP encrypts data on a wireless network by using a fixed secret key. WEP incorporates a checksum in each frame to provide protection against the attacks that attempt to reveal the key stream. Answer option A is incorrect. Extensible Authentication Protocol (EAP) is an authentication protocol that provides support for a wide range of authentication methods, such as smart cards, certificates, one-time passwords, public keys, etc. It is an extension to Point-to-Point Protocol (PPP), which allows the application of arbitrary authentication mechanisms for the validation of a PPP connection. Answer option C is incorrect. Internet Protocol Security (IPSec) is a method of securing data. It secures traffic by using encryption and digital signing. It enhances the security of data as if an IPSec packet is captured, its contents cannot be read. IPSec also provides sender verification that ensures the certainty of the datagram's origin to the receiver. Reference: "http://en.wikipedia.org/wiki/Wi-Fi_Protected_Access"

• Question 32:

  Which of the following statements is true about the installation of Universal Serial Bus (USB) devices?

  A. A USB device can be plugged to a computer without restarting it.

  B. A computer has to be restarted to install a USB device.

  C. USB devices are non-Plug and Play.

  D. Software drivers are not required for USB devices.

  Correct Answer: A

  Universal Serial Bus (USB) is a high speed bus standard developed by Compaq, IBM, DEC, Intel, Microsoft, NEC, and Northern Telecom. It provides the Plug and Play capability of Windows to external hardware devices. USB supports hot plugging, which means that a USB device can be installed or removed while the computer is running. A single USB port can be used to connect up to 127 peripheral devices, such as CD-ROM drives, tape drives, keyboards, scanners etc. USB 1.1 has a maximum data transfer rate of 12 Mbps, whereas USB 2.0 has a maximum data transfer rate of 480 Mbps. USB 2.0 is fully backward compatible with USB 1.1. Answer option D is incorrect. Software drivers are required for USB devices. It is possible, though, that the drivers for your USB devices are already available on the computer. In this case, you do not need to provide a device driver separately. Answer option B is incorrect. It is not required to restart the computer to install USB devices. Reference: TechNet, Contents: "Universal Serial Bus Support for Windows CE"

• Question 33:

  Which of the following are types of access control attacks?

  Each correct answer represents a complete solution. Choose all that apply.

  A. Brute force attack

  B. Mail bombing

  C. Spoofing

  D. Dictionary attack

  Correct Answer: ABC

  The following are types of access control attacks : 1.Spoofing 2.Brute force attack 3.Dictionary attack 4.Denial of service attack What is spoofing? Spoofing is a technique that makes a transmission appear to have come from an authentic source by forging the IP address, email address, caller ID, etc. In IP spoofing, a hacker modifies packet headers by using someone else's IP address to his identity. However, spoofing cannot be used while surfing the Internet, chatting on-line, etc. because forging the source IP address causes the responses to be misdirected.

  What is dictionary attack?

  Dictionary attack is a type of password guessing attack. This type of attack uses a dictionary of common words to find out the password of a user. It can also use common words in either upper or lower case to find a password. There are

  many programs available on the Internet to automate and execute dictionary attacks.

  What is a brute force attack?

  In a brute force attack, an attacker uses software that tries a large number of the keys combinations in order to get a password. To prevent such attacks, users should create passwords more difficult to guess, e.g., using a minimum of six

  characters, alphanumeric combinations, and lower-upper case combinations, etc. Answer option B is incorrect. Mail bombing is not a type of access control attack. Mail bombing is an attack that is used to overwhelm mail servers and clients

  by sending large amount of unwanted e-mails. The aim of this type of attack is to completely fill the recipient's hard disk with immense, useless files, causing at best irritation, and at worst total computer failure. E-mail filtering and properly

  configuring email relay functionality on mail servers can be helpful for protection against this type of attack.

• Question 34:

  Which of the following uses a shorter wavelength and allows for almost six times more data storage than on a DVD?

  A. Blu-ray Disc

  B. Digital Linear Tape (DLT)

  C. Bluetooth

  D. Blue Jacking

  Correct Answer: A

  Blu-ray Disc, also known as Blu-ray or BD, is an optical disc storage medium. It is designed to supersede the standard DVD format for storing high-definition video, PlayStation 3 games, and other data, with up to 25 GB per single layered, and

  50 GB per dual layered disc. Blu-ray Disc was developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, and motion pictures. The disc has the same physical dimensions as

  standard DVDs and CDs. It is called Blu-ray Disc because of the blue-violet laser which is used to read the disc. Blu-ray uses a shorter wavelength, a 405 nm blue-violet laser, and allows for almost six times more data storage than on a DVD.

  Answer option C is incorrect. Bluetooth is a standard for very low powered and short-range radio connections. It is used to link personal access devices (PDA), mobile phones and laptops, and provides them with Internet access via hot spots.

  Bluetooth uses the 2.4 Ghz spectrum with a data rate of about 1 Mbps. As a radio technology, Bluetooth does not require line of sight like an infrared connection requires. The maximum transmission range of Bluetooth is around 10 meters.

  Highpowered

  Bluetooth would extend the range to 100 meters.

  Answer option D is incorrect. Blue Jacking is the process of sending unsolicited messages over

  Bluetooth to Bluetooth-enabled devices such as mobile phones, PDAs or laptop computers, sending

  a vCard which typically contains a message in the name field to another Bluetooth enabled device

  via the OBEX protocol.

  Answer option B is incorrect. Digital Linear Tape (DLT) is a magnetic tape data storage technology developed by Digital Equipment Corporation (DEC). DLT drives support hardware data compression.

  Media are guaranteed for 30 years of data retention under specified environmental conditions. However, they are easily damaged by mishandling. Current manuurers of cartridges for the DLT market are Fujifilm, Hitachi/Maxell and Imation.

  Reference: "http://en.wikipedia.org/wiki/Blu-ray_Disc"

• Question 35:

  Which of the following are a form of online advertising on the World Wide Web intended to attract

  Web traffic or capture email addresses?

  A. Pop-ups

  B. Signed script policy:

  C. Cookies

  D. Java applet

  Correct Answer: A

  Pop-up ads or pop-ups are a form of online advertising on the World Wide Web intended to attract Web traffic or capture email addresses. It works when certain Web sites open a new Web browser window to display advertisements. The pop-up window containing an advertisement is usually generated by JavaScript, but can be generated by other means as well. Answer option C is incorrect. A cookie is a small bit of text that accompanies requests and pages as they move between Web servers and browsers. It contains information that is read by a Web application, whenever a user visits a site. Cookies are stored in the memory or hard disk of client computers. A Web site stores information, such as user preferences and settings in a cookie. This information helps in providing customized services to users. There is absolutely no way a Web server can access any private information about a user or his computer through cookies, unless a user provides the information. A Web server cannot access cookies created by other Web servers. Answer option B is incorrect. Signed script policy is a policy in which testing is required to check the identity of a user sending requests from a Web browser. In this policy, when a receiver receives a request from the user to access some resources of his computer, he can grant or deny the access on the basis of whether the request is coming from a trusted or a non-trusted source. If the receiver permits the request, the code will run on the browser after further checks. An author converts the code in the form of an encrypted text, which is recreated on the browser as a simple text. The code will not run on the browser if there is any modification in the text. Answer option D is incorrect. A Java applet is a software program written in Java language. It is distributed as an attachment in a Web document and executed in a Java-enabled Web browser. Java applets can run on almost any operating system without requiring recompilation.

• Question 36:

  How many devices can be connected to an IEEE 1394 port?

  A. 63

  B. 127

  C. 256

  D. 1

  Correct Answer: A

  An IEEE 1394 port can connect upto 63 devices. This port is also known as FireWire.

  What is the IEEE1394 connector?

  The IEEE1394 (FireWire) connector is used with the FireWire serial bus. FireWire can transmit data at a very high speed of 400Mbps and 800Mbps. Two types of connectors are available in this category, namely 4-pin and 6-pin. Answer

  option B is incorrect. A single USB port can be used to connect upto 127 peripheral devices.

  Reference: TechNet, Contents: "http://www.webopedia.com/TERM/I/IEEE_1394.html"

• Question 37:

  You are responsible for purchasing computer hardware for a school district. You have been looking at various sales brochures advocating various types of memory.

  What would be one advantage to buying dual-channel memory?

  A. It will reduce memory bottlenecks.

  B. It will be twice as fast as single channel memory.

  C. It has no advantage over single channel memory.

  D. It will have more memory capacity than single channel memory.

  Correct Answer: A

  Dual Channel memory offers two channels for data to move through it. This may reduce bottle necks.

  Answer options B and D are correct. The dual or single channel issue is unrelated to memory speed or capacity.

  Answer option C is incorrect. It will have an advantage over single channel, though the advantages are slight.

  Reference: http://www.pcextreme.net/reviews/ram/dual-channel-vs-single-memory- configuration/

• Question 38:

  Which of the following do not support encrypted data transmissions?

  A. Ethernet devices

  B. Infrared devices

  C. Wi-Fi devices

  D. Bluetooth devices

  Correct Answer: B

  The infrared devices do not encrypted data transmission. Infrared technology uses invisible infrared radiations to transmit signals to short distances. There are two types of communication possible: one in which the sender and the receiver

  are visible to each other and are situated in a straight line. This is known as line-of-sight mode; the other type of communication known as diffuse mode does not require the sender and receiver to be directly visible to each other. This

  technology is used in TV sets, cordless microphones, laptops, remote modems, printers, and other peripheral devices.

  Answer options D, A, and C are incorrect. The Bluetooth, Ethernet, and Wi-Fi devices supports encrypt data transmissions.

  Reference: TechNet, Contents: "Wireless Networking"

• Question 39:

  Which of the following types of batteries are used by toys and watches?

  A. Silver oxide

  B. Zinc-air

  C. Lead-acid

  D. Silver lead

  Correct Answer: A

  The Silver oxide batteries are used in toys and watches. These batteries can become highly hazardous at the end of their useful life. After a period of use (approximately five years), the batteries may begin to leak their contents which contain

  mercury, posing a serious health risk.

  Answer option C is incorrect. The Lead-acid batteries are used in Car, Golf Cart, UPS, Industrial Fork-

  Lift, Motorcycle, etc.

  Answer option B is incorrect. The Zinc-air batteries are used in hearing aids and in older cameras that previously used mercury batteries.

  Answer option D is incorrect. There is no such battery as Silver lead. Reference: "http://en.wikipedia.org/wiki/Battery_recycling#Types_of_batteries"

• Question 40:

  Which of the following statements about a docking station are true?

  Each correct answer represents a complete solution. Choose two.

  A. It allows a laptop to connect to desktop I/O devices such as full-sized keyboards, CRT monitors, etc.

  B. Docking station is also known as a workstation.

  C. It is a large circuit board found in a computer on which a CPU is mounted.

  D. It is a specialized case into which an entire laptop can be inserted.

  Correct Answer: AD

  A docking station is a specialized case into which an entire laptop can be inserted. This allows the laptop to connect to desktop I/O devices such as full-sized keyboards, CRT monitors, etc. Docking stations are highly proprietary items that are

  designed for use with specific computer models. It is useful for a user who wants to maintain only one computer system and avoid transferring information between two computers. With a docking port and a well-equipped laptop, a user can

  get the environment of both a laptop and a desktop computer.

  Answer option C is incorrect. A motherboard is a large circuit board found in a computer on which a

  CPU is mounted.

  Answer option B is incorrect. A workstation is a computer in a network from where a user works.