Computer Science Midterm

computing network

a group of connected computers that can send or receive data

computing device

a machine that can run a program

Convert the decimal (base-10) number 20 to binary (base-2).

10100

Packets

segments of messages that contain digital instructions that allow them to reassemble properly at the same time at the destination

HTTP (Hypertext Transfer Protocol)

the protocol used for transmitting web pages over the Internet

What is the difference between lossy and lossless compression

Lossy compression algorithms are typically better than lossless compression algorithms at reducing the number of bits needed to represent a piece of data. Lossless keeps the data as close to its original form.

Jorge is sending a large image file to a friend as part of a shared classroom project. What is most likely true if Jorge opts to compress the image before sending it?

The image will require fewer bits in order to be represented.

Conditional Statement

affects the sequential flow of control by executing different statements based on the value of a Boolean expression

bit

binary digit

Lossy Compression

data compression techniques in which some amount of data is lost. This technique attempts to eliminate redundant information.

Your computer uses 4 bits to represent decimal numbers (0, 1, 2, 3 and so on) in binary. What is the SMALLEST number for which an overflow error occur?

16

Internet Protocol (IP)

A set of rules responsible for disassembling, delivering, and reassembling packets over the Internet.

How many total numbers can be represented with an 8-bit binary (base-2) system

256 (zero is a number)

Convert the binary (base-2) number 1001 to decimal (base-10).

9

In which of the following stages of the development process is a team MOST likely to interview a potential user of an app? A. investigating and reflecting B. designing C. prototyping D. testing

A

Which of the following Internet protocols is MOST important in reassembling packets and requesting missing packets to form complete messages? A. Transmission Control Protocol (TCP) B. Internet Protocol (IP) C. User Datagram Protocol (UDP) D. HyperText Transfer Protocol (HTTP)

A

Which of the following binary (base-2) numbers is LARGEST? A. 11000000 B. 01111111 C. 00000001 D. 10111111

A

How do computing devices represent information?

A computer represents data as bits which is either a 0 or a 1

IP address

A number assigned to any item that is connected to the Internet.

Arman takes a picture with his smartphone which he subsequently posts online. Beatrice finds the picture online and posts a copy of it on her website with an attached Creative Commons license. Which of the following best describes who owns the photo? A. Beatrice owns the photo because only holders of a Creative Commons license can own works online. B. Arman owns the photo because he was the original creator and did not license the work. C. Arman owns the photo because it was granted a Creative Commons license by another person online. D. Both own the photo because creating a copy makes it her intellectual property.

B

Which of the following is MOST likely to be an outcome of the digital divide? A. Certain companies will be unable to certify their technology as digitally secure. B. People from some racial or ethnic groups have unequal access to computing technology. C. People will have equal access and influence both globally and locally. D. Political groups in some countries are unable to agree on regulations of digital technology.

B

Which of the following is true of functions? A. Programs written with functions run more quickly B. Functions can help remove repeated code from a program C. Replacing repeated code with a function will reduce the number of commands the computer needs to run D. Functions are called once but can be declared many times

B

Boolean Expression

Evaluates to either true or false; used in the conditional of an if-structure.

Which of the following is NOT true of how computers represent complex information? A. Computing devices use patterns of bits to represent complex information B. Abstraction helps represent complex information by surfacing complexity that might otherwise be hidden C. Depending on context the same sequence of bits may represent different types of information D. Common abstractions that are represented by computing devices include numbers, characters, and color.

B; Abstraction is filtering out - ignoring - the characteristics of patterns that we don't need in order to concentrate on those that we do

An Internet Service Provider (ISP) is a company that builds the routers and wired connections that allow individuals to access the Internet.An ISP is considering adding additional redundant connections to its network. Which of the following best describes why the company would choose to do so? A. It costs less to design a network that is redundant B. The protocols of the Internet only work on networks that are redundant C. Redundant networks are more reliable D. Adding additional connections reduces the fault-tolerance of the network

C

Which of the following is true of how the Internet has responded to the increasing number of devices now using the network? A. The Internet protocols are changed every year to adapt to the new devices that have been connected to the network B. While the number of devices connected to the Internet has grown, the network itself has not grown C. The protocols of the Internet were designed to scale as new devices are added D. The protocols of the Internet are no longer necessary thanks to the large number of devices now connected to the network

C

Emilee is watching an online video. The video is being sent to her laptop by a server over the Internet which splits the video into packets and sends them in the order they appear in the video. Which of the following is true about how the packets will arrive at her computer? A. The packets will always be received in the order that they were sent B. Either every packet will reach her computer or none of them will. C. Packets that arrive out of order will be sent back to the server. D. The packets may arrive out of order

D

Lucy is completing a project as part of a science class using materials she found online. Which of the following is MOST LIKELY to lead to legal consequences? A. Modifying a piece of open source software. B. Using open access research for which she does not acquire a license. C. Failing to publish her work under a Creative Commons license. D. Using images posted online by another student without permission or citation.

D

Two devices are connected to the Internet and communicating with one another. A squirrel chews through one of the wires in the network that is currently being used by the devices to communicate. The network immediately begins using a different path through the network and communication continues as normal. This is an example of...

Fault Tolerance

Which Internet protocols is used to request and send pages and files on the World Wide Web?

HTTP

When visiting a museum Lian takes a photo of a painting with a smartphone which stores the photo as an image file. Which of the following best describes the differences between the painting itself and the photo of the painting stored on the smartphone?

The photo is a digital representation of the analog painting

TCP vs UDP (transport layer protocols)

The speed for TCP is slower while the speed of UDP is faster. TCP does error checking and also makes error recovery, on the other hand, UDP performs error does not.

Which of the following is true of how computers represent numbers?

With a fixed number of bits some numbers are too large to represent in a computer which will lead to overflow errors.

Lossless Compression

a data compression algorithm that allows the original data to be perfectly reconstructed from the compressed data.

Byte

a group of 8 bits

computing system

a group of computers working together for a common purpose

path

a sequence of direct connections

Which of the following is NOT a reason to include comments in programs A. Comments help the computer decide whether certain components of a program are important. B. Comments help programmers debug issues in their own code C. Comments help document how code was written for other programmers to use D. Comments enable programmers to track their work throughout the development process

A

Which of the following situations is most likely to cause issues arising from the digital divide? A. A state makes voter registration forms available only by visiting a government website B. Two internet-connected devices located in different countries and thousands of miles apart attempt to communicate with one another C. Packets sent from one router to another begin arriving in a different order than they were sent D. A smartphone attempts to communicate over the Internet with another type of device, like a tablet or laptop

A

Creative Commons

A kind of copyright that makes it easier for people to copy, share, and build on your creative work, as long as they give you credit for it.

Which of the following is true of how packets are sent through the Internet? A. Packet metadata is only included on important packets to indicate they should get access to faster paths through the network B. Packet metadata is used to route and reassemble information travelling through the Internet C. Information sent through the internet is only encapsulated in packets if the message is too large to be sent as a datastream D. Information sent through the internet is split into two packets, one which contains the message and another which contains the metadata

B

Which of the following best describes the purpose of a design specification? A. Tracking errors that arise through user testing B. Documenting comments that will need to be added to a program C. Describing the requirements for how a program will work or users will interact with it D. Listing detailed questions that will be asked of users during interviews

C

Which of the following is true of intellectual property? A. Information created on a computer is not owned by anyone since only analog information is protected under copyright law. B. You do not need to cite work created by someone else if both the original work and your use of it are in digital form. C. Creative Commons enables content creators to freely distribute their otherwise copyrighted work. D. Creative Commons has severely hindered broad and open access to digital information

C

14. Ryan is designing an app that needs to quickly send low quality photos between users. Most smartphones take much higher quality photos than Ryan needs for his app. Which answer best describes the type of compression Ryan should choose and why? A. Lossless compression since it ensures perfect reconstruction of the photo. B. Lossy compression since it ensures perfect reconstruction of the photo. C. Lossless compression since it typically results in smaller data sizes. D. Lossy compression since it typically results in smaller data sizes.

D

Which of the following best describes the protocols used on the Internet? A. The protocols of the Internet are designed by government agencies to ensure they remain free to use B. The protocols of the Internet are secret to maintain the privacy and security of people using them C. Each device connected to the Internet will use a protocol designed by the company that manufactured it D. The protocols of the Internet are open and used by all devices connected to the network

D

Which of the following best describes the purpose of an IP address? A. IP addresses provide a unique number for identifying devices that send and receive information on the Internet B. IP addresses assist in the reconstruction of a message that has been divided into many packets C. IP addresses indicate the location where an internet-connected computing device was manufactured D. IP addresses indicate how many times an individual packet has been requested by a router

A

Jesse purchases a new smartphone and is immediately able to use it to send a photo over the Internet to a friend who lives in a different country. Which of the following is NOT necessary to make this possible? A. Both devices are using the same shared and open protocols B. A single direct connection is established between any two devices connected to the Internet C. The data of the image is routed through a sequence of directly connected devices before arriving at its destination. D. Both devices are directly connected to at least one part of the Internet

B

Which of the following BEST describes the differences between sequential and event-driven programming? A. In sequential programming commands run one at a time. In event-driven programming all commands run at the same time. B. In sequential programming commands run faster than in event-driven programming. C. In sequential programming each command is run many times in sequence. In event-driven programming all commands are run a single time as an event. D. In sequential programming commands run in the order they are written. In event-driven programming some commands run in response to user interactions or other events.

D