Computer Science Mid term study guide-- Questions

Number systems with different bases such as binary (base-2), 0ctal (base-8), decimal (base 10), and hexadecimal (base-16), are all used to view and represent digital data. Which of the following is NOT true about representing digital data?

When data is, large enough computers switch to using decimal representation instead of binary, because you can represent larger numbers with fewer digits.

According to the domain name system (DNS), which of the following is the subdomain of the domain example.com?

about.example.com

Consider the following three binary numbers 01010 010000 1110 Which of the following lists the numbers in order from LEAST TO GREATEST?

01010 1110 010000

What is the 4-bit binary for the decimal number ten (10)?

1010

How many total bits bits would it take to represent the smallest possible image (i.e. an image with one pixel)?

18 bits

How many total bits would there be in the the largest possible image we could make with the pixelation widget (assuming 1 bit per pixel)?

2. 255 x 255 x8=520,200

Two students have developed a protocol in which they send 4-bit messages to each other. They decide to modify their protocol to start sending 8-bit messages instead. How many more values can be represented in an 8-bit message than a 4-bit message

24 = 16 times as many values

What are the dimensions (width and height) of the largest image we can make with the pixelation widget?

255 x 255

Identify the two true statements about HTTP.

A. An HTTP request is sent from a client to request access to data stored on a server. C. An HTTP request is sent from a client to request access to data stored on a server.

Choose the two (2) statements that are true about functions

A. Meaningful function names help people better understand programs. D. Functions in programming are named groupings of programming instructions.

Why is the Vigenere cipher hard to crack? (select 2)

A. One cannot solve using frequency analysis directly. B. The key length is variable and potentially very long

ASCII characters can also be represented by binary numbers. According to ASCII character encoding, which of the following letters is represented by the 8-bit binary value: 0100 0010

ASCII Character B

Radio Wave

Alternating Frequencies

Which of the following is the most accurate description of what is known as the "digital divide". The digital divide is about how...

B. ...people's access to computing and the Internet differs based on socioeconomic or geographic characteristics.

The word "Apple" translated into its ASCII number (decimal) equivalent is: A. 097 112 112 108 101 B. 065 112 112 108 101 C. 041 108 108 111 119 D. 097 108 108 111 119 E. 065 110 110 105 101

B. 065 112 112 108 101

Which of the following is NOT true about packets?

B. A message sent across the Internet can always be contained in a single packet

What is a function parameter?

B. A way to give input to a function that controls how the function runs.

A binary message consisting of four bits was sent to you by a friend. The message was supposed to be ABAB. Unfortunately, your friend set the bit on the wire once every 2 seconds, but you read the wire once every second. Assuming that the first bit was sent and read at the same time, what message did you receive instead? A. ABAB B. AABB C.AAAA D. BBBB E. ABBB

B. AABB

Consider these various uses of randomNumber. Each answer describes the use and shows a code example. Which one of the following is NOT a valid use of randomNumber A. Calling the parameters of a function B. Defining the parameters of a function C. Moving the turtle around the screen D. Orienting the direction of the turtle E. Setting pen properties F. None of the above

B. Defining the parameters of a function

Select the two true statements about functions with parameters

B. Functions with parameters can be used to prevent the creation of duplicated code. C. Parameters help generalize the solution of a specific problem.

What feature of DNS and IP allow the internet to scale?

B. Hierarchy

Historically it has been observed that computer processing speeds tend to double every two years. This is known as:

B. Moore's Law

Which of the following statements are true about pivot tables? Select two answers.

B. Pivot tables are used to quickly perform aggregate computations and groupings on a set of raw data D. Pivot tables are used to generate a summarized view of a large dataset which is helpful for gaining insight

What is an RFC? A. Restricted Fiduciary Contract B. Request For Comments C. Radio Frequency Controller D. Related Fundamental Content E. ReFactored Code

B. Request For Comments

Pick the two statements about packets and routing on the Internet which are true.

B. TCP ensures messages can be reliably transmitted across the Internet D. TCP must account for the fact that packets may not arrive at a destination computer in the intended order

What is the "key" to a Caesar Cipher that someone needs to know (or discover) to decrypt the message?

B. The number of characters to shift each letter in the alphabet

A single central register of IP addresses and names (a DNS style system) is an efficient means of translating human readable names to IP addresses. Which of the following is NOT solved by DNS?

B. There are too few IP addresses to meet the current demand.

Fiber Optic Cable

Beam of Light

The Caesar Cipher has 25 different shifts to try. How many possibilities are there to try in a random substitution cipher?

C. 26 × 25 × 24 ×···× 3 × 2 x 1

What is 20 MOD 15?

C. 5

If you just had two shapes (say, a circle and a square), how many 3-place patterns could you make? A. 4 B. 6 C. 8 D. 10 E. 12

C. 8

The Internet Engineering Task Force (IETF) defines the protocols and standards for how the Internet works. The members of the IETF are: A. An International coalition of government agencies who oversee the Internet in their countries. B.The worldwide leaders of the Tier 1 Internet service providers. C. A loosely organized collection of citizens and engineers who communicate mostly by email. D. Political leaders and heads of state. E. There are no members. IETF is an "organization" in name only.

C. A loosely organized collection of citizens and engineers who communicate mostly by email.

What is an API?

C. Application Program Interface

Which of the following is NOT part of defining a function?

C. Giving the parameters a value

To improve communication in playing battleship on the Internet Simulator your group invented a(n): A. Heuristic B. Algorithm C. Protocol D. Encoding

C. Protocol

In the Internet Simulator, your router knows to send your message to a different router because: A. You set the "other router" bit in the message. B. Everyone is on the same router. C. The first 4 bits of the address specify the router number that your friend is on. D. Messages are routed over different paths.

C. The first 4 bits of the address specify the router number that your friend is on.

When a computer scientist uses the term "Big Data" what do they typically mean?

C. There is enough data processing applications are inadequate

Which of the following statements about writing functions and Top-Down Design is NOT true?

C. Two programmers solving the same problem using Top-Down Design should arrive at identical programs.

Which of the following blocks is least similar to the others? A. moveTo (x, y) B. turnLeft (angle) C. arcRight (angle, radius) D. moveForward (pixels)

C. arcRight (angle, radius)

When responding to a question with 4 choices, the most efficient method will require _____ number of bits. A. 5 bits B. 4 bits C. 3 bits D. 2 bits E. 1 bit

D. 2 bits

How many bits? ASCII has an encoding for every character of the alphabet as well as encodings for numbers -- that is, encodings for the symbols of the digits 0-9. So here is a trick question: How many bits are required to store the text of the number "150" in ASCII?' A. 3 bits B. 8 bits C. 16 bits D. 24 bits E. 32 bits

D. 24 bits

How many bytes does it take...? How many bytes (or bits) are required to encode an image that is 25 pixels wide and 50 pixels tall, if you encode each pixel with 3 bytes (24 bits) of RGB data. (Don't forget to add in the metadata! -- you should assume that we are using the file format used in this lesson with metadata that had 1 byte each for width, height and bits-per-pixel.)

D. 3,753 bytes (30,024 bits)

What is the minimum number of bits you need to encode the 26 letters of the alphabet plus a space? A. 2 bits B. 3 bits C. 4 bits D. 5 bits E. 6 bits

D. 5 bits

How many unique IP addresses could be made in a fixed-length IP address system using 6 bits? A. 6 users B. 12 users C. 32 users D. 64 users

D. 64 users

Which two of the following statements are true about routing on the Internet.

D. A packet travelling between two computers on the Internet may be rerouted many times along the way. E. A packet contains addressing information to allow routers to decide how best to forward along that packet towards its destination.

Which of the following statements is the LEAST TRUE about personal data that technology companies potentially collect about their users?

D. Companies are required by law to give users options to personalize what data they collect about them

Which of the following is the most accurate statement about cleaning and filtering data?

D. Filtering and cleaning data is necessary to ensure that data is in a form that is better for computers to process

HTTP is considered to be a high level protocol because:

D. HTTP requests make use of abstractions provided by lower level protocols.

What is 13 MOD 17?

D.13

From the list provided choose the two answers that correctly describe which internet protocol relies on the other. For example if protocol A relies on protocol B it means that A is higher level protocol than B, and thus protocol B must exist and work properly in order for protocol A to do its Job. Select two answer.

DNS Relies on TCP/P, HTTP relies on TCP/IP

The standard QWERTY keyboard has 47 keys that can place characters on the screen. Each of these keys can also display a second character by holding the "Shift" key at the same time. How many bits would you need to encode everything that could be typed on this keyboard? A. 3 bits B. 4 bits C. 5 bits D. 6 bits E. 7 bits F. 12 bits

E. 7 bits

Which of the following is NOT a true statement about functions?

E. Functions cannot make calls to other functions written by the same programmer.

Copper Wire

Electric Voltage

The world is currently in transition to using IPv6, a newer version of the IP protocol that uses 128 bit addresses instead of 32-bit addresses used by !Pv4. What is the main problem that IPv6 was created to solve?

IPv6 will allow problems with IPv4's address hierarchy to be resolved

A user clicks on a website, and it begins to load immediately, but it takes a long time to load completely and pictures appear slowly, one by one. Which of the following is demonstrated through this situation?

Low bandwidth, Low Latency