CSP Unit 1 Review

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

• 3

• 5

• 6

What is the best explanation for why digital data is represented in computers in binary?

• The binary number system is the only system flexible enough to allow for representing data other than numbers.

• It's easier, cheaper, and more reliable to build machines and devices that only have to distinguish between binary states.

• It typically takes fewer digits to represent a number in binary compared to other number systems.

• It's impossible to build a computing machine that uses anything but binary to represent numbers.

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

• 0010

• 1010

• 0110

• 0101

Number systems with different bases such as binary (base-2) and decimal (base-10) are all used to view and represent digital data. 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. 

• The same value (number) can have a different representation depending on the number system used to represent it. 

• Groups of bits can be used to represent abstractions, including but not limited to numbers and characters. 

• Some large numbers cannot be represented in binary and can only be represented in decimal.

Which BEST describes metadata?

• It can be compared to a card catalog in the library - not the book itself, but information about the book.

• Information, often quantitative or qualitative, stored by a computer and use in its operations and calculations.

• After or beyond; often used to describe abstraction.

• A collaborative meeting of statisticians, computer programmers, economists, and others at which data are discussed, analyzed, and processed.

Which of the following is a true statement about 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 state.

• 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.

Which of the following can be represented by a sequence of bits?

I. An integer

II. A character

III. A sound wave

• I only

• II only

• I and II

• I, II, and III

TikTok has perfected it's FYP by analyzing the data that you spend on the app. The following is a small list of data they have collected: 

● Time and day the user is on the app

●      The hashtags on the videos the user "likes"

●      How long a user watches a certain hashtag

●      What videos the user creates containing hashtags

Which of the following questions CANNOT be answered by looking at the information above?

• How long did a user spend watching #catvideos on Thursday?

• How many videos did the user "like" with #schooliscool?

• Which profile does the user interact with the most?

• Which hashtags does the user like watching at 7am on Wednesdays?

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?

• 14

• 15

• 16

• 17

Which of the following is true of lossy and lossless compression algorithms?

• Lossy compression algorithms are used when perfect reconstruction of the original data is important.

• Lossy compression algorithms are typically better than lossless compression algorithms at reducing the number of bits needed to represent a piece of data.

• Lossless compression algorithms are only used to compress text data.

• Lossless compression algorithms only allow for an approximate reconstruction of the original data.