Unit 2 Part 2 Study Guide

A bank customer receives an e-mail from a sender claiming to be a bank employee. The e-mail asks the customer to provide personal information and to call a phone number if he or she has any questions. The customer suspects the e-mail might be a phishing attempt. Which of the following responses is most likely to be a privacy risk for the bank customer?

Responses

A

Calling the bank at its official phone number to ask whether the request for personal information is legitimate

B

Calling the phone number given in the e-mail and providing the personal information over the phone

C

Checking that the domain name of the sender’s e-mail address is associated with the bank

D

Conducting aWeb search to see if other people have received similar requests for personal information

B Calling the phone number given in the e-mail and providing the personal information over the phone

Which of the following best describes the role of the Internet Engineering Task Force (IETF) ?

Responses

A

Developing standards and protocols for Internet communication

B

Preventing copyrighted materials from being illegally distributed online

C

Preventing malicious software from being distributed online

D

Verifying the ownership of encrypted keys used in secured messages

A Developing standards and protocols for Internet communication

A smartphone stores the following data for each photo that is taken using the phone.

• The file name of the photo

• The date and time the photo was taken

• The geographic location where the photo was taken

Assume that all of the photos that have been taken on the phone are accessible. Which of the following can be determined using the photo data described above?

      I. The number of photos that were taken at a particular geographic location
     II. The number of photos that were taken in the last year
    III. The name of the person who took the most recent photo

Responses

A

III only

B

I and II only

C

I and III only

D

I, II, and III

B I and II only

Which of the following is a true statement about Internet communication?

Responses

A

Devices from different manufacturers are required to run the same operating system to communicate over the Internet.

B

Every device connected to the Internet is assigned a digital certificate by a certificate authority.

C

Every device connected to the Internet is assigned an Internet protocol (IP) address.

D

Every device connected to the Internet requires a high-bandwidth connection to enable redundant routing to each device.

C Every device connected to the Internet is assigned an Internet protocol (IP) address.

A library of e-books contains metadata for each book. The metadata are intended to help a search feature find books that users are interested in. Which of the following is LEAST likely to be contained in the metadata of each e-book?

Responses

A

An archive containing previous versions of the e-book

B

The author and title of the e-book

C

The date the e-book was first published

D

The genre of the e-book (e.g., comedy, fantasy, romance, etc.)

A An archive containing previous versions of the e-book

The following figures represent different ways of configuring a network of physically linked computers labeled P, Q, R, and S. A line between two computers indicates that the computers can communicate directly with each other. In which configuration is it NOT possible to have redundant routing between computers P and S?

Responses

A

B

C

D

B

Byte pair encoding is a data encoding technique. The encoding algorithm looks for pairs of characters that appear in the string more than once and replaces each instance of that pair with a corresponding character that does not appear in the string. The algorithm saves a list containing the mapping of character pairs to their corresponding replacement characters.

For example, the string  can be encoded as  by replacing all instances of  with and replacing all instances of  with .

Which of the following statements about byte pair encoding is true?

Responses

A

Byte pair encoding is an example of a lossy transformation because it discards some of the data in the original string.

B

Byte pair encoding is an example of a lossy transformation because some pairs of characters are replaced by a single character.

C

Byte pair encoding is an example of a lossless transformation because an encoded string can be restored to its original version.

D

Byte pair encoding is an example of a lossless transformation because it can be used to transmit messages securely.

C Byte pair encoding is an example of a lossless transformation because an encoded string can be restored to its original version.

Byte pair encoding is a data encoding technique. The encoding algorithm looks for pairs of characters that appear in the string more than once and replaces each instance of that pair with a corresponding character that does not appear in the string. The algorithm saves a list containing the mapping of character pairs to their corresponding replacement characters.

For example, the string  can be encoded as  by replacing all instances of  with and replacing all instances of   with .

For which of the following strings is it NOT possible to use byte pair encoding to shorten the string’s length?

Responses

A

B

C

D

B. LEVEL UP

A text-editing application uses binary sequences to represent each of 200 different characters. What is the minimum number of bits needed to assign a unique bit sequence to each of the possible characters?

Responses

A

4

B

6

C

7

D

8

D. 8

Which of the following explains a benefit of using open standards and protocols for Internet communication?

Responses

A

Open standards and protocols allow different manufacturers and developers to build hardware and software that can communicate with hardware and software on the rest of the network.

B

Open standards and protocols provide ways for users to eliminate the latency of messages they send on the Internet.

C

Open standards and protocols allow users to freely share or reuse material found on the Internet for noncommercial purposes.

D

Open standards and protocols prevent developers from releasing software that contains errors.

A. Open standards and protocols allow different manufacturers and developers to build hardware and software that can communicate with hardware and software on the rest of the network.

Internet protocol version 4 (IPv4) represents each IP address as a 32-bit binary number. Internet protocol version 6 (IPv6) represents each IP address as a 128-bit binary number. Which of the following best describes the result of using 128-bit addresses instead of 32-bit addresses?

Responses

A

4 times as many addresses are available.

B

96 times as many addresses are available.

C

 times as many addresses are available.

D

 times as many addresses are available.

D. 2^96 times as many addresses are available

A computer program uses 4 bits to represent nonnegative integers. Which of the following statements describe a possible result when the program uses this number representation?

I. The operation  will result in an overflow error.

II. The operation  will result in an overflow error.

III. The operation  will result in an overflow error.

Responses

A

I only

B

II only

C

II and III only

D

I, II, and III

B. II only

In public key cryptography, the sender uses the recipient’s public key to encrypt a message. Which of the following is needed to decrypt the message?

Responses

A

The sender’s public key

B

The sender’s private key

C

The recipient’s public key

D

The recipient’s private key

D. The recipient’s private key

Which of the following is an example of symmetric encryption?

Responses

A

Evy buys a locked box that operates using two different codes. When the first code is entered, a slot opens that allows a message to be put in the box. When the second code is entered, the door to the box opens. Evy gives the first code to her friends so they can leave messages for her and keeps the second code to herself so that she is the only one who can retrieve the messages.

B

Finn and Gwen develop a system that maps each letter of the alphabet to a unique symbol using a secret key. Finn uses the key to write a message to Gwen where each letter is replaced with the corresponding symbol. Gwen uses the key to map each symbol back to the original letter.

C

Hannah writes a message to send to Isabel and hides the message under a rock behind the soccer field. Hannah gives Isabel the exact location of the rock so that only Isabel can find the message.

D

Juan writes a message to send to Kelly and slides the message through a slot in the front of Kelly’s locker. Juan knows that Kelly has not shared her locker combination with anyone, so no one other than Kelly will be able to read the message.

B. Finn and Gwen develop a system that maps each letter of the alphabet to a unique symbol using a secret key. Finn uses the key to write a message to Gwen where each letter is replaced with the corresponding symbol. Gwen uses the key to map each symbol back to the original letter.

A media librarian at a movie studio is planning to save digital video files for archival purposes. The movie studio would like to be able to access full-quality videos if they are needed for future projects. Which of the following actions is LEAST likely to support the studio’s goal?

Responses

A

Using video file formats that conform to published standards and are supported across many different devices

B

Using lossy compression software to reduce the size requirements of the data being stored

C

Using storage media that can be expanded for additional data capacity

D

Using a system that incorporates redundancy to handle disk failure

B. Using lossy compression software to reduce the size requirements of the data being stored.

Which of the following statements describes how cloud computing has affected Internet communication?

Select two answers.

response - correct

Responses

A

Cloud computing has eliminated the need to provide redundancy in Internet routing.

B

Cloud computing has helped enhance collaboration.

C

Cloud computing has introduced new data security concerns.

D

Cloud computing has reduced concerns about intellectual property rights.

B. Cloud computing has helped enhance collaboration.

C. Cloud computing has introduced new data-security concerns.

Which of the following best explains how an analog audio signal is typically represented by a computer?

Responses

A

An analog audio signal is measured as input parameters to a program or procedure. The inputs are represented at the lowest level as a collection of variables.

B

An analog audio signal is measured at regular intervals. Each measurement is stored as a sample, which is represented at the lowest level as a sequence of bits.

C

An analog audio signal is measured as a sequence of operations that describe how the sound can be reproduced. The operations are represented at the lowest level as programming instructions.

D

An analog audio signal is measured as text that describes the attributes of the sound. The text is represented at the lowest level as a string.

B. An analog audio signal is measured at regular intervals. Each measurement is stored as a sample, which is represented at the lowest level as a sequence of bits.

Which of the following can be represented by a single binary digit?

Select two answers.

response - correct

Responses

A

The position of the minute hand of a clock

B

The remainder when dividing a whole number by 2

C

The value of a Boolean variable

D

The volume of a car radio

B. The remainder when dividing a whole number by 2

C. The value of a Boolean variable

A video-streaming Web site uses 32-bit integers to count the number of times each video has been played. In anticipation of some videos being played more times than can be represented with 32 bits, the Web site is planning to change to 64-bit integers for the counter. Which of the following best describes the result of using 64-bit integers instead of 32-bit integers?

Responses

A

2 times as many values can be represented.

B

32 times as many values can be represented.

C

2³² times as many values can be represented.

D

32² times as many values can be represented.

C. 2³² times as many values can be represented

An office uses an application to assign work to its staff members. The application uses a binary sequence to represent each of 100 staff members. What is the minimum number of bits needed to assign a unique bit sequence to each staff member?

Responses

A

5

B

6

C

7

D

8

C. 7

Two computers are built by different manufacturers. One is running a Web server and the other is running a Web browser. Which of the following best describes the ability of the two computers to communicate with each other across the Internet?

Responses

A

The computers cannot communicate because different manufacturers use different communication protocols.

B

The computers can communicate, but additional hardware is needed to convert data packets from one computer’s protocol to the other computer’s protocol.

C

The computers can communicate directly only if the messages consist of text; other formats cannot be interpreted across computers.

D

The computers can communicate directly because Internet communication uses standard protocols.

D. The computers can communicate directly because Internet communication uses standard protocols.

The figure below represents a network of physically linked devices labeled A through I. A line between two devices indicates that the devices can communicate directly with each other.

Any information sent between two devices that are not directly connected must go through at least one other device. For example, in the network represented below, information can be sent directly between A and B, but information sent between devices A and G must go through other devices.

Which of the following statements is true about the network?

Responses

A

Information sent from device A to device D can use at most two unique paths.

B

Information sent from device A to device I will pass through at most four other devices.

C

If devices B and F fail, then device A will not be able to communicate with device G.

D

If devices C and F fail, then device D will not be able to communicate with device H.

C. If devices B and F fail, then device A will not be able to communicate with device G.

The figure below represents a network of physically linked devices labeled A through I. A line between two devices indicates that the devices can communicate directly with each other.

Any information sent between two devices that are not directly connected must go through at least one other device. For example, in the network represented below, information can be sent directly between A and B, but information sent between devices A and G must go through other devices.

What is the minimum number of connections that must be broken or removed before device B can no longer communicate with device C?

Responses

A

Three

B

Four

C

Five

D

Six

B. Four

Which of the following statements about the Internet is true?

Responses

A

The Internet is a computer network that uses proprietary communication protocols.

B

The Internet is designed to scale to support an increasing number of users.

C

The Internet requires all communications to use encryption protocols.

D

The Internet uses a centralized system to determine how packets are routed.

B. The Internet is designed to scale to support an increasing number of users.

A programmer is developing software for a social media platform. The programmer is planning to use compression when users send attachments to other users. Which of the following is a true statement about the use of compression?

Responses

A

Lossless compression of video files will generally save more space than lossy compression of video files.

B

Lossless compression of an image file will generally result in a file that is equal in size to the original file.

C

Lossy compression of an image file generally provides a greater reduction in transmission time than lossless compression does.

D

Sound clips compressed with lossy compression for storage on the platform can be restored to their original quality when they are played.

C. Lossy compression of an image file generally provides a greater reduction in transmission time than lossless compression does.

A user enters a Web address in a browser, and a request for a file is sent to a Web server. Which of the following best describes how the file is sent to the user?

Responses

A

The file is broken into packets for transmission. The packets must be reassembled upon receipt.

B

The file is broken into packets for transmission. The user’s browser must request each packet in order until all packets are received.

C

The server attempts to connect directly to the user’s computer. If the connection is successful, the entire file is sent. If the connection is unsuccessful, an error message is sent to the user.

D

The server repeatedly attempts to connect directly to the user’s computer until a connection is made. Once the connection is made, the entire file is sent.

A. The file is broken into packets for transmission. The packets must be reassembled upon receipt

Researchers have developed a simulation of packets traveling between server computers and client computers in a network. Of the following, which two outcomes are most likely to be results of the simulation?

Select two answers response - correct

Responses

A

Better understanding of the effect of temporarily unavailable network connections

B

Better understanding of the effect of using hexadecimal representations for binary data

C

Better understanding of the impact of access to public data in identifying solutions to problems

D

Better understanding of the impact of increased connection speeds for frequently visited servers

A. Better understanding of the effect of temporarily unavailable network connections

D. Better understanding of the impact of increased connection speeds for frequently visited servers

A student is recording a song on her computer. When the recording is finished, she saves a copy on her computer. The student notices that the saved copy is of lower sound quality than the original recording. Which of the following could be a possible explanation for the difference in sound quality?

Responses

A

The song was saved using fewer bits per second than the original song.

B

The song was saved using more bits per second than the original song.

C

The song was saved using a lossless compression technique.

D

Some information is lost every time a file is saved from one location on a computer to another location.

A. The song was saved using fewer bits per second than the original song.

Digital images are often represented by the red, green, and blue values (an RGB triplet) of each individual pixel in the image. A photographer is manipulating a digital image and overwriting the original image. Which of the following describes a lossless transformation of the digital image?

Responses

A

Compressing the image in a way that may lose information but will suffer only a small loss of image quality.

B

Creating the gray scale of an image by averaging the amounts of red, green, and blue in each pixel and assigning this new value to the corresponding pixel in the new image. The new value of each pixel represents a shade of gray, ranging from white to black.

C

Creating the negative of an image by creating a new RGB triplet for each pixel in which each value is calculated by subtracting the original value from 255. The negative of an image is reversed from the original; light areas appear dark, and colors are reversed.

D

Modifying part of the image by taking the pixels in one part of the picture and copying them to the pixels in another part of the picture.

C. Creating the negative of an image by creating a new RGB triplet for each pixel in which each value is calculated by subtracting the original value from 255. The negative of an image is reversed from the original; light areas appear dark, and colors are reversed.

The figure below represents a network of physically linked devices, labeled A through F. A line between two devices indicates a connection. Devices can communicate only through the connections shown.

Which of the following statements are true about the ability for devices A and C to communicate?

Select two answers.

response - correct

Responses

A

If devices B and D were to fail, then information sent from device A could not reach device C.

B

If devices B and F were to fail, then information sent from device A could not reach device C.

C

If devices D and F were to fail, then information sent from device A could not reach device C.

D

If devices E and F were to fail, then information sent from device A could not reach device C.

A. If devices B and D were to fail, then information sent from device A could not reach device C.

C. If devices D and F were to fail, then information sent from device A could not reach device C.

The figure below represents a network of physically linked devices, labeled A through H. A line between two devices indicates a connection. Devices can communicate only through the connections shown.

What is the minimum number of connections that would need to be removed from the network in order for device A to not be able to communicate with device F?

Responses

A

2

B

3

C

4

D

5

A. 2

Which of the following best explains what happens when a new device is connected to the Internet?

Responses

A

A device driver is assigned to the device.

B

An Internet Protocol (IP) address is assigned to the device.

C

A packet number is assigned to the device.

D

A Web site is assigned to the device.

B. An Internet Protocol (IP) address is assigned to the device.

Which of the following best explains how the Internet is a fault-tolerant system?

Responses

A

The Internet is fault-tolerant because cybercriminals can conceal their actions, allowing them the ability to carry out faulty actions without leaving a trace.

B

The Internet is fault-tolerant because there are usually multiple paths between devices, allowing messages to sometimes be sent even when parts of the network fail.

C

The Internet is fault-tolerant because users can transmit messages using a variety of different protocols, allowing them to use devices from any manufacturer.

D

The Internet is fault-tolerant because users usually understand and accept the fact that servers sometimes fail, allowing network engineers to repair faulty devices as quickly as possible.

B. The Internet is fault-tolerant because there are usually multiple paths between devices, allowing messages to sometimes be sent even when parts of the network fail.

Which of the following statements correctly explain how the Internet is able to facilitate communication at a large scale?

1. A central monitoring computer is used to track and maintain the connections of the Internet.

2. Data is routed between points in multiple ways so that if a connection fails, the data can be rerouted around the inoperative connections.

3. Protocols for packets and routing are used so that computers from different manufacturers can communicate in a standard way.

Responses

A

I and II only

B

I and III only

C

II and III only

D

I, II, and III

C. II and III only

Which of the following best explains how messages are typically transmitted over the Internet?

Responses

A

The message is broken into packets that are transmitted in a specified order. Each packet must be received in the order it was sent for the message to be correctly reassembled by the recipient’s device.

B

The message is broken into packets. The packets can be received in any order and still be reassembled by the recipient’s device.

C

The message is broken into two packets. One packet contains the data to be transmitted and the other packet contains metadata for routing the data to the recipient’s device.

D

The message is transmitted as a single file and received in whole by the recipient’s device.

B. The message is broken into packets. The packets can be received in any order and still be reassembled by the recipient’s device.