129 questions
Which is true about a router?
Protocols ensure that a single path between two computers is established before sending packets over it.
Routers are hierarchical and the "root" router is responsible for communicating to sub-routers the best paths for them to route internet traffic.
A packet traveling between two computers on the Internet may be rerouted many times along the way or even lost or "dropped"
Which is true about a router?
Protocols ensure that a single path between two computers is established before sending packets over it.
Routers act independently and route packets as they see fit.
Routers are hierarchical and the "root" router is responsible for communicating to sub-routers the best paths for them to route internet traffic.
The various protocols in use on the internet are said to operate in layers in which the protocols at each layer solve one problem related to networked communication, and higher layers are built on top of, and rely on, the lower layers to do their jobs.
From the list provided which internet protocol relies on the other?
TCP/IP relies on HTTP
HTTP relies on TCP/IP
TCP/IP relies on DNS
DNS relies on HTTP
The various protocols in use on the internet are said to operate in layers in which the protocols at each layer solve one problem related to networked communication, and higher layers are built on top of, and rely on, the lower layers to do their jobs.
From the list provided which internet protocol relies on the other?
TCP/IP relies on HTTP
DNS relies on TCP/IP
TCP/IP relies on DNS
DNS relies on HTTP
A sample of a company's tracking information collected on their computers appears above. Which of the following is MOST likely to be answerable using all the data collected by this monitoring?
Which employees are visiting social media sites from work
Which employees are doing the most work using the computers
Which programs employees are running on the computers
Which websites are most frequently visited before and after work hours from a work computer
Which of the following BEST describes how protocols on the Internet make use of abstraction to accomplish their respective purposes?
High level protocols take into account specific implementation details of lower level protocols to ensure they are compatible.
Low level protocols can provide functionality to high level protocols without revealing the details of how this is accomplished.
High level protocols can take on the role of a low level protocol in the event of failure in the system.
Low level protocols are written in binary while high level protocols are written in hexadecimal
According to the domain name system (DNS), which of the following is a subdomain of the domain example.com?
about.example.com
example.co.uk
example.com.org
example.org
Which of the following is NOT true about TCP/IP packets?
Packets are numbered so if they arrive out of order the message can be reassembled.
TCP guarantees that no packets are ever dropped
Packets can be routed on different paths from sender to receiver.
Messages are broken into packets to improve reliability of the internet
The Internet Engineering Task Force (IETF) defines the protocols and standards for how the Internet works. The members of the IETF are:
An International coalition of government agencies who oversee the Internet in their countries.
A collection of the leaders of the Tier 1 Internet service providers.
A loosely organized collection of citizens and engineers.
Political leaders and heads of state.
How does a computer resolve a domain name into an IP address?
It asks a DNS server for the corresponding IP address
It scans addresses until it finds the one it's looking for
It uses a Border Gateway Protocol to get the address from a nearby computer.
It creates an IP address for the domain, and shares it with the closest DNS.
The figure represents a network of physically linked computers labeled A through F. A line between two computers indicates that the computers can communicate directly with each other. Any information sent between two computers that are not directly connected must go through at least one other computer. The weight or cost of sending information from one computer to another is indicated by the number above the line.
For example, information can be sent directly between computers A, and B and will cost 5. Information sent between computers A and D must go through either computer C (with total cost 5), or through computer B (with total cost 8).
Computer A sends a packet intended to reach computer F. Along its path it arrives at Computer C. Which computer should Computer C forward the packet to in order to use the most cost effective path?
Computer A
Computer B
Computer D
Computer F
The world is currently in a transition to using IPv6, a newer version of the IP protocol that uses 128-bit addresses instead of 32-bit addresses used by IPv4. What is the main problem that IPv6 was created to solve?
32-bit addresses could not accommodate the increased size and amount of data traveling on the Internet as it has grown in popularity
IPv6 will allow problems with IPv4's address hierarchy to be resolved
IPv4 proved unreliable in some cases where network redundancy could not be ensured
32-bit addresses could not ensure that every internet-connected device can receive a unique IP address
_____ provides reliable, ordered, and error-checked delivery of a stream of packets on the internet. It is tightly linked with IP.
TCP
DNS
HTTP
URL
______ is a simplified representation of something more complex. It allows you to hide details to help you manage complexity, focus on relevant concepts, and reason about problems at a higher level.
Net Neutrality
Protocol
Abstraction
Latency
_____ is the principle that all Internet traffic should be treated equally by Internet Service Providers.
Abstraction
Net Neutrality
Protocol
Latency
Octal Number System
Which of the following is TRUE regarding lossless and lossy compressions?
An example of lossless compression is a .jpg file
Lossless uses inexact approximations while lossy does not·
You can completely reconstruct lossless but not lossy compression ·
You can completely reconstruct lossy but not lossless compression
All of the following would be shown in metadata except:
Width and Height of an Image
Type of Compression
Number of Colors
Resolution
Which of the following is FALSE regarding file sizes?
1 Terabyte = 1,000 kilobytes
1 Petabyte = 1,000 Terabytes
1 Megabyte = 1,000 bytes
1 Terabyte = 1,000 gigabytes
Which of the following is FALSE regarding types of files and the file sizes they are measured in?
A .jpg (JPEG) file is typically measured in megabytes
The entire amount of information transferred over the entire Internet is typically measured in terabytes
A .txt file is typically measured in kilobytes
An .mov file is typically measured in gigabytes
Your best friend has 50 small images to send to you; each of which is 500 KB. How much space do they take up overall in MB?
25 MB
250 MB
2.5 MB
25,000 MB
You have 1100 MB of data. Your best friend has 3000 MB of data. Will all of this data fit on your 4 GB thumb drive?
Yes, all this data will fit on the thumb drive
No, The data will not fit on the thumb drive
A problem solving approach to find a satisfactory solution where finding an optimal or exact solution is impossible (for example, with compression) is called ________________.
simplistic
heuristic
abstraction
How many bytes 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 (Note: in addition, there are also 24 bits of metadata)
1,250 bytes
3,774 bytes
3,750 bytes
249 bytes
Which of the following is TRUE regarding data compression?
Data compression is only useful for files being transmitted over the Internet
Regardless of the compression technique used, once a data file is compressed, it cannot be restored to its original size.
Sending a compressed version of a file ensures that the contents of the file cannot be intercepted by an unauthorized user.
There are trade-offs involved in choosing a compression technique for storing and transmitting data.
A student is transferring photos from her camera to her computer. The student notices that the saved photos on her computer are lower quality than the original raw photo on her camera.
Which of the following could be a possible explanation for the difference in image quality?
The saved image files were compressed with a lossy compression technique.
The saved image files were compressed with a lossless compression technique.
The saved image files were not compressed properly.
Some information is lost every time a file is saved on a computer.
Under which of the following conditions is it most beneficial to use a heuristic approach to solve a problem?
When the problem can be solved in a reasonable time and an approximate solution is acceptable
When the problem can be solved in a reasonable time and an exact solution is needed
When the problem cannot be solved in a reasonable time and an approximate solution is acceptable
When the problem cannot be solved in a reasonable time and an exact solution is needed
Which of the following correctly shows the hexadecimal value for Red as a 12-bit representation.
F00
00F
FF00
FF0001
To uncompress the data back into its original binary state, you simply reverse the process. This technique is an example of what type of compression?
Lossy Compression
Lossless Compression
FFT Compression
Tailored Compression
In very broad terms the MP3 audio compression algorithm identifies frequencies and volume levels - low and high - that are outside the range of human hearing and removes the data representing these frequencies from the original.
This technique results in a smaller audio file that sounds exactly the same to the human ear. This technique is an example of what type of compression?
Lossy Compression
Lossless Compression
FFT Compression
Tailored Compression
Approximately how much bigger (how many more bytes) is a megabyte than a kilobyte?
1,000 times bigger
10,000 times bigger
100,000 times bigger
1,000,000 times bigger
The term that defines data about the data is called _____.
megadata
superdata
metadata
predata
Programming languages have some similarities and differences to the "natural" language you use in everyday speech. Select the two true statements about programming languages:
Ambiguities in natural language necessitate the creation of programming languages for controlling a computer
Compared to the number of words in a natural language, the number of defined words in a programming language is very small.
The number of defined words in a programming language is about the same as the number of words in a natural language.
There are typically many possible ways to interpret an instruction written in a programming language.
Which of the following images shows the path and ending location of the robot that will result from executing the code above. The starting location of the robot is shown as dotted triangle for cases where the robot does not start and end at the same location.
REPEAT 4 TIMES {
MOVE_FORWARD()
MOVE_FORWARD()
MOVE_FORWARD()
ROTATE_RIGHT(90)
MOVE_FORWARD()
ROTATE_RIGHT(90)
MOVE_FORWARD()
ROTATE_RIGHT(90)
}
Consider the following incorrect program, which is intended to move the robot around the perimeter of a grid, as indicated by the drawing below. The starting position and direction of the robot is indicated in the diagram.
Line 1: 4 TIMES
Line 2: {
Line 3: MOVE_FORWARD()
Line 4: ROTATE_RIGHT()
Line 5: MOVE_FORWARD()
Line 6: MOVE_FORWARD()
Line 7: MOVE_FORWARD()
Line 8: MOVE_FORWARD()
Line 9: ROTATE_RIGHT()
Line 10: }
Given the options below, which lines should be removed so the program will work as intended?
Line 3 and Line 4
Lines 5, 6, 7, 8 and 9
Line 8 and Line 9
Line 9
Which of the following is NOT true about functions in programming?
Functions are reusable programming abstractions.
Functions help reduce the complexity of writing and maintaining programs.
Functions cannot make calls to other functions within the same program.
Once defined, a function can be called many times from different parts of a program.
Functions help break a problem into logical chunks.
What is one important naming convention of functions?
A function name should indicate how long the function takes to run.
Two functions with similar behavior should be given identical names to indicate the relationship between them.
A function name should be as descriptive as possible to indicate what the function does.
Function names should be organized alphabetically.
The function name should begin with a number that indicates the order in which it should be executed.
Which one of the following statements about functions is TRUE?
A function can change names over the course of a program.
Code can be added or removed dynamically from a function while the program is running.
Functions can be called using different names depending on where in the program they are called.
Two functions can be given identical names as long as their code is identical.
Two functions in a single program can have different names but contain identical code.
A problem solving approach (also known as stepwise design) in which you break down a system to gain insight into the sub-systems that make it up.
Top Down Design
Function
Variable
You will need to use the Top-Down Design Strategy to create a program to design a snowflake. Make sure you a using logical chunks and have reasonable names for your chunks of programming.
Review Lesson 6 on Code.org
Review Lesson 6 on Code.org
Which of the following will call the function drawStar?
drawStar
drawStar();
function drawStar (){
for(var i=0; i <5; i++) {moveForward(100); turnLeft(36):}}
function drawStar;
function drawStar();
For this scenario related to turtle drawing, indicate whether it is better to write a loop or a function (or a set of functions) to handle the task:
Drawing out the letters of a word "HELLO"
Loop
Function
For this scenario related to turtle drawing, indicate whether it is better to write a loop or a function (or a set of functions) to handle the task:
Drawing a hexagon (six-sided shape)
Loop
Function
For this scenario related to turtle drawing, indicate whether it is better to write a loop or a function (or a set of functions) to handle the task:
Drawing 100 tiny dots in a line.
Loop
Function
For this scenario related to turtle drawing, indicate whether it is better to write a loop or a function (or a set of functions) to handle the task:
Drawing a circle of any size at any point on the screen.
Loop
Function
Why are parameters useful when programming?
Parameters determine the number of times the function will run.
Parameters allow for more flexible, generalized behaviors in functions.
Parameters are useful for teams of programmers because they help define the boundaries of the problem they are trying to solve.
Parameters change the order of operations within a function.
What is the most likely outcome of running the code shown at right?
It will draw a star with each side 150 pixels long.
The program will stop with an error at line 3 because parameters may not be used in for loops.
The program will stop with an error at line 5 because it is dividing by 0.
The program will run without error, but will not draw anything.
When programmers work together, what is an example of how abstraction in programming can promote collaboration?
Team members can rely on one another to explain their code.
Programmers can write functions without needing to know what they do or how they should work.
Programmers can use functions created by their partners, relying on the functionality without needing to know the specific details of how the function is implemented.
In order for programmers to work together, they must work in the same room.
Abstraction allows programmers to brainstorm more creative solutions to problems.
Which of the following images represents the most likely output produced by the code segment given below?
Explain how abstraction allows for the creation of increasingly complex systems. Reference top-down design strategy in your response.
You need to know how to do this. Review Lesson 9
You need to know how to do this.Review Lesson 9
Why are these icons a good use of abstraction?
They tell us what they mean without needing to use the name
They are difficult to understand
They don't explain what they are
What is the point of binary?
It represents how computers interpret electrical signals
Because we like to make you do extra maths ;-D
It takes fewer digits to represent a number
Because it describes star systems
Why do computers use binary to represent digital data?
Binary is more flexible than other number systems and allows better representations.
It's easier, cheaper and more reliable to distinguish between 2 states of data.
It typically takes less digits to represent data in binary than other number systems.
Binary is the only way to build a machine.
What is the minimum number of bits you would need to encode the 26 letters of the alphabet plus a space - a total of 27 characters
2 bits
3 bits
5 bits
6 bits
Which of the following is NOT true about representing digital data?
At one of the lowest levels of abstraction, all digital data can be represented in binary using only combinations of the digits zero and one.
Some large numbers cannot be represented in binary and can only be represented in decimal.
Groups of bits can be used to represent abstractions, including but not limited to numbers and characters.
The same value (number) can have a different representation depending on the number system used to represent it.
A company database has each customer's unique ID number stored as an 10-bit number called customerID. The company is expanding and most of the their 10-bit number has already been assigned to a student. Of the options below which is the smallest change to the way customerID is represented necessary to ensure each new customer receives a uniqueID?
Remove a bit from customerID to make room for incoming customers.
Double the number of bits in customerID to double the number IDs that the database can represent.
Add a bit to customerID to double the number of IDs that the database can represent.
Keep using the 10-bit number for customerID but reserve the first bit to indicate old or new customers.
Which of the following is true about the way digital data is transmitted on the Internet?
Bit-rate (bandwidth) is the time elapsed between the transmission and receipt of a piece of digital data.
Digital data can only be transmitted between two devices when they are physically connected to one another (for example by a copper wire)
Latency is the amount of data (measured in bits) that can be sent in a fixed amount of time.
Two devices must communicate using the same bit-rate to successfully send and receive digital data.
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?
21 = 2 times as many values
22 = 4 times as many values
23 = 8 times as many values
24 = 16 times as many values
______ encryption is a method of encryption involving one key for both encryption and decryption
Symmetric
Asymmetric
Public key
SSL
Which of the following most accurately describes Moore's Law?
Moore's Law describes a relationship of boolean logic statements involving AND and OR
Moore's Law is the principle that one should assume that any traffic on the Internet is insecure
Moore's Law is the observation that computing power tends to double every two years
Moore's Law explains why cracking modern cryptography is a "computationally hard" problem
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?
The sender's public key
The sender's private key
The recipient's public key
The recipient's private key
How do Internet packets travel to their destination?
Router to router based on the Travelling Salesman algorithm
Along the same path to stay in order
Timed to arrive at the destination in their correct order
Along a variety of different paths
What are brute-force attacks?
Attacks that use frequency analysis to break passwords
Attacks that check each possible solution to break encrypted data
Attacks against DNS servers to enable DDOS attacks
Attacks on firewalls to gain access to a company's sensitive data
What is a symmetric key used for?
Sending and receiving information from the web
Encrypting data
Decrypting data
Encrypting and decrypting data
What is the definition of bandwidth?
The frequency that data can be transmitted across the Internet
The speed that data can be sent through the Internet
The amount of data that can be transmitted in a fixed amount of time
The delay between the request and the receipt of information on the Internet
What is the purpose of DNS? (Domain Name System)
To translate natural language website names to their IP address.
To create a new IP address for a website each time it is requested.
To position the packets in the correct order.
To route the Internet request on the way to its destination.
What is the most common way computer viruses are spread?
By people clicking on an infected file
From pop up ads
Through network worms
From random botnet attacks
The protocol used for transmitting web pages over the Internet is called ...
HTML.
HTTP.
DNS.
TCP/IP.
What does the s in https refer to?
It's the plural of http - a more robust version of http that runs on multiple channels.
s is for "secure" - a version of http that is encrypted.
s is for "simple" - a simplified version of http that runs faster on modern computers
s is for "standard" - to distinguish the original http from non-standard versions like httpv and httpx
When someone tries to get you to give up personal information through email or a bogus website it is called a: *
DDoS Attack
Phishing Scam
Virus
SSL/TLS layer
How is the Internet scalable?
Through the ability for additional networks and routers to be added without impacting service.
Through the ability to add longer public keys to keep data secure
Through the ability to add additional authentication for users
Through the ability to add additional latency to requests
What is 20 MOD 15?
0
5
15
20
What is the "key" to a Caesar Cipher that someone needs to know (or discover) to decrypt the message?
A secret word only know by Caesar.
The number of characters to shift each letter in the alphabet.
The letter that occurs most often in the encrypted message.
The day of the month that the encrypted message was sent
Which of the following is the most accurate description of what is known as the "digital divide". The digital divide is about how...
...people's access to computing and digital technology increases over time through a process of dividing and growing quickly - it is often likened to the biological processes of cell growth
...people's access to computing and the Internet differs based on socioeconomic or geographic characteristics.
...people's access to computing technology is affected by the fact that newer devices that use new protocols makes it more difficult for them to communicate with older devices and technology
...the amount of data on the Internet is growing so fast that the amount computing power and time we have to process it is lagging behind
Which of the following statements best describes the properties of public key encryption?
Public key encryption is an encryption method which relies on separate keys for encrypting and decrypting information.
Public key encryption is a highly secure encryption scheme that in which a single shared key is used by both the sender and receiver of the message.
Public key encryption makes use of certain types of problems which are easier for humans to solve than computers.
Public key encryption makes use of mathematical problems which no algorithm can be used to solve.
When a computer scientist uses the term "Big Data" what do they typically mean?
That a dataset is larger than 5TB which is the common "Big Data" threshold.
That there is so much data it's virtually impossible to process.
There is enough data that traditional data processing applications are inadequate.
It implies that the findings from the data are potentially hugely important for society.
How can financial transactions safely occur on the Internet?
Through the use of symmetric keys
Through certificates issued by Certificate Authorities (CAs) that validate the keys used
Through the use of double authentication methods
The the use of frequency analysis
A coffee shop is considering accepting orders and payments through their phone app and have decided to use public key encryption to encrypt their customers' credit card information. Is this a secure form of payment?
No, public key encryption allows the credit card information to be read by the public.
No, the internet protocols are open standards and thus everything sent over the internet is sent "in the clear".
Yes, public key encryption is built upon computationally hard problems that even powerful computers cannot easily solve.
Yes, public key encryption is secure because it transmits credit card information in binary.
Pick the two expressions involving the Modulo operation that compute to the exact same value (choose 2)
9 MOD 8
1 MOD 16
52 MOD 32
9 MOD 64
Choose the answer that is NOT a feature of Public Key Cryptography:
A key for decrypting is never made public
Using public key guarantees that only the intended recipient can decrypt the message
A Public Key database ensures 3rd party accountability of security
Allows secure communication without establishing a *shared* encryption key ahead of time.
A programmer is writing a system that is intended to be able to store large amounts of personal data. As the programmer develops the data system, which of the following is LEAST likely to impact the programmer's choices in designing the structure of the system?
Maintaining privacy of the information stored in the data set.
Scalability of the system.
Structuring the metadata of the information for analysis.
The frequency of a particular item occurring in a data set.
What is a Distributed Denial of Service (DDoS) attack?
A coordinated effort by a group to simultaneously attempt to gain entry to foreign government's servers or systems
An effort by network engineers to focus all systems on catching a user or computer that has illegally gained access.
An attempt to compromise a single target by flooding it with requests from multiple systems.
An attempt to harass or extort all customers of one or more Internet Service Providers (ISPs).
Which of the following scenarios is most characteristic of a phishing attack.
You accidentally run a piece of code that automatically spreads from one computer to another, exploiting a common vulnerability
You get an email from the IT support desk that asks you to send a reply email with your username and password to verify your account
You get an unwanted email trying to sell you a low quality product or service that seems "fishy."
You accidentally install a piece of software that monitors your activity to steal personal information like your passwords, date of birth, social security number, etc.
Which of the following are true statements about digital certificates in Web browsers?
I. Digital certificates are used to verify the ownership of encrypted keys used in secured communication
II. Digital certificates are used to verify that the connection to a Web site is fault tolerant.
I only
II only
I and II
Neither I nor II