APCSP Encoding and Internet Quiz Review

What is the formula for finding the amount of combinations in a certain amount of bits?

2^bits = combinations, where the ‘bits’ is simply the amount of bits you have.

What happens when you add a zero to the right side of a binary number?

It multiplies the value by 2, so if 0011=3, than 00110=6

Are the binary numbers 0011 and 000011 the same?

Yes, adding more zeros to the left does not change the total value

Two of these are true -
A) Using more bits per character will allow more letter combinations
B) Using more bits per character has no negative effects
C) Using more bits per character means the message will come through clearer
D) Using more bits per character will take up more storage space, which is bad

A, D

Two of these could be represented by 3 bits. Which two?
A) 8 directions of a compass (N, NE, E, SE, S, SW, W, NW)
B) A book on my bookshelf (with 63 books)
C) Each student in a class of 16 people
D) Position of a lightbulb (on or off)

A, D

A preschool uses 8 bits to help students learn to count. What is the highest number that these students can count up to?
A) 127
B) 128
C) 255
D) 256

C

What is a byte?

A value of 8 bits

An alien language has 2^{21 characters. WHat is the minimum number of BYTES that I need to encode this language?
A) 1
B) 2
C) 3
D) 4}

C

What is analog data?

A term used to mean something with continuous representation, like a picture you draw on paper, smooth and steady no matter how much.

What is digital data?

A term used to mean something with incosistent, discrete representation, like somebody running at different paces and even stopping at some point.

Which of the following is NOT true about analog and digital data?
A) Digital Data is discrete and discontinuous
B) More frequent sampling means the data is more analog and less digital
C) Analog data is smooth and continuous
D) Audio playing from a piano is an example of digital data

D

Which of the following is LEAST true about converting a live music performance to digital?

A) The live audio is an example of analog data
B) More frequent sampling means the digital recording will more closely approximate the live performance than if using less frequent sampling
C) Digital version of the performance is created whgen the audio is rounded to either a 0 or a 1, whichever is closer
D) Digital version of the performance is created when the audio is sampled at regular time intervals, then converted to bits

C

How many times more colors can you represent with 6 bits/pizel vs 3 bits/pixel?
A) 2³
B) 2
C) 3
D) 3²

A

How many times bigger is your file size if you represent your image with 6 bits/pixel vs 3 bits/pixel
A) 2³
B) 2
C) 3
D) 3²

B

What is lossless compression?

A type of compression that is reversible - meaning it can go back to the original file size, but can’t take much data at once

What is lossy compression?

A big, giant, compression that can handle lots of data but it loses some of the information and is not reversible

What is the most important quality of lossless compression?

A) The data is transformed to usually make it smaller. It can always be re-constructed back to the original.

B) The data is transformed to always make it smaller. It cannot always be re-constructed back to the original.

C) The data is transformed to always make it smaller. It can always be re-constructed back to the original.

D) The data is transformed to usually make it smaller. It cannot always be re-constructed back to the original.

C

. I might prefer lossy compression over lossless compression in this scenario?

A) I want to temporarily compress an image to put 

on my phone and restore it later.

B)  When I have unlimited internet bandwidth.

C) I have a text file, and need to know 100% what 

the text says after it is compressed.

D) I am very short on space on my computer and 

need maximum space.

D

One of these is a lossless transformation. Which?
A) Invert each color by subtracting each RGB value from 255
B) Take each RGB value and apply MOD 10 to it
C) Drop every 10th pixel and reduce the resolution so that it’s easy to send the picture
D) Convert image to gray by averaging RGB values

A

If using lossless compression, one of these is most compressible. Which?

A )    AABBAABBAABBAABB

B)    ABABABABABABABAB

C )   AAAAAAAAAAAAAAAA

D  ) ABABBABBBABBBBABBBBB

C

What is the primary purpose of the Internet?

Communication

The Internet was made to survive a nuclear bomb. What two terms describe this?

Fault Tolerance and Redundancy

The code.org video talks about breaking up internet messages into blocks before sending them across the internet.  What are these blocks called?

Packets

What is a computer network?

A group of interconnected computing devices that can send or receive data

What is routing?

The process of finding a networking path from sender to reciever

What is redundancy in networking?

Duplicating critical components, data, or pathways to ensure it keeps running

What is Fault Tolerance?

A system’s ability to keep running without interruption when one or more parts of the hardware break

One of these is false about routing on the internet

 

 A     Fault-tolerant routing allows data to be sent and 

received, even if some connections are not 

operational

 B     A redundant computer network can be created 

with 3 nodes (computing devices) and 2 

connections.

 C     Redundancy in the internet allows me to 

download a file, even if some computing devices 

are not working

 D     Multiple paths between computing devices helps 

create a network that can still deliver messages, 

even if a component has failed.

B

What is the minimum number of connections that can be broken so that device A can no longer communicate with device H?
A) 1
B) 2
C) 3
D) 4

B

What is the maximum number of connections that can be severed and device A can still communicate with device H?
A) 6
B) 7
C) 8
D) 9

D

One of these is false:
A) The path between devices A and C is Fault Tolerant
B) If devices E and F fail, A will not be able to communicate with J
C) If devices I and G fail, A will not be able to communicate with J
D) E and F can communicate directly with each other without any other device knowing

C

What is a protocol?

A set of rules that govern how data is transmitted, received, and interpreted between two different devices on a network

What protocol forms the basis for all Internet communication?

Internet Protocol (IP)

What is an IP?

Rules for addressing and sending data where everybody has a specific number

Which is true?

1. Redundancy makes the internet fault-tolerant, at the cost of slowing down sending messages

2. If I add a routing device on the internet, messages will not use this new device unless there is an interruption in the current path.

3. Redundancy helps enable privacy on the internet

 A     I only

 B     II only

 C     II and III

 D     None of the above

D

What is Protocol #!?

The UDP - faster than protocol #2, but more prone for erros

What is Protocol #2?

The TCP - slower than Protocol #1 but less prone for errors

What are packets?

Chunks of data and its metadata used to route and assemble information on the internet, meaning messages come in packet data streams instead of one, big message

What is the Internet?

An interconnected, network with protocols

What is the World Wide Web?

Linked pages, attractions, programs and files (like your tabs)

What is HTTP?

A protocol where your browser practically talks to the website

Is this Internet, WWW, or HTTP?
A tab with YouTube shorts opened on it

WWW

Is this Internet, WWW, or HTTP?
Logging into your Supercell account

HTTP

Is this Internet, WWW, or HTTP?
Deleting a comment on a TikTok post.

HTTP

Is this Internet, WWW, or HTTP
The whole World Wide Web.

Internet

Which of these protocols is most used for with sharing Web pages across the Internet?
A) UDP
B) TCP
C) HTTP
D) IP

C

What is Certificate Authority?

A trusted organization that verifies online identities and issues digital certificates to secure websites, apps, and devices. Like McAfee, or other virus catchers.

What is Sequential Computing?

Solving issues and/or operations strictly one after another

What is parallel computing?

Fast, simultaneous computing to quickly solve objectives by splitting up the work on one singular computer

What is distributed computing?

Like parallel, but instead of done on one computer, it can be as many as you want.

A task consists of three steps: Step 1 takes 10 seconds, Step 2 takes 15 seconds, and Step 3 takes 5 seconds. If these steps must be performed sequentially, what is the total execution time? 
A    10 seconds 

B    15 seconds 

C    25 seconds 

D     30 seconds 

D

Consider a program with a 5-second sequential setup phase followed by three parallel tasks: Task A (10s), Task B (12s), and Task C (8s). If run on a system that can execute all parallel tasks simultaneously, what is the total execution time?

A   17 seconds 

B     25 seconds 

C    35 seconds 

D     12 seconds 

A

What fundamentally limits the potential speedup gained from parallel computing, even with an increasing number of processors? 

A    The amount of storage the computer can access

B    The size of the parallel portion 

C    The inherent sequential portion of the task 

D    The number of available computing devices 

C

A computer has 2 processors. Process A takes 10s. Process B takes 12s. Process C takes 14s. Process D takes 16s. They are all independent. What is the minimum execution time? 

A    26s

B    28s

C    30s

D   52s

A

How many combinations can you make with 10 bits? (2¹⁰)

1024

For a minimum number of bits question, what do you need to remember?

That the question is asking for a possible number of combinations, and if it asks how many bits would be needed to have each of 5 different things have a separate number , you do the formula