APCSP Practice Test Flashcards

Questions and Answers

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

As a consequence of history: early pioneers of computing were making secret codes in binary, and this simply evolved into modern computing.

The binary number system is the only number 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. (correct)

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

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

1010 (correct)

0110

0101

0010

What is the minimum number of bits you need to encode the 26 letters of the alphabet plus a space - a total of 27 characters?

2 bits

5 bits (correct)

3 bits

6 bits

Which of the following is NOT true about representing digital data?

There is a limit to the number of things that can be represented in binary data at which point switching to hexadecimal representation is necessary. Signup and view all the answers

Which of the following lists the numbers in order from least to greatest? BIN: 1110, DEC: 13, HEX: F

DEC: 13, BIN: 1110, HEX: F Signup and view all the answers

Which is the most accurate description of how a school could modify the way studentID is represented in the database to ensure each incoming student receives a unique ID?

Add a bit to studentID to double the number of IDs that the database can represent. Signup and view all the answers

Which of the following is demonstrated if 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?

Low bandwidth, low latency Signup and view all the answers

How many total bits do you need to represent 512 (twice as many) numbers?

9 bits Signup and view all the answers

What is the ASCII value of the uppercase letter 'G'?

71 Signup and view all the answers

Study Notes

Binary Data Representation

Digital data in computers is represented in binary because it is easier, cheaper, and more reliable to build devices that distinguish between two states (0 and 1).

Number Systems

The 4-bit binary representation for the decimal number 10 is 1010.

Encoding Characters

A minimum of 5 bits is required to encode 27 characters, such as the 26 letters of the alphabet plus a space.

Understanding Number Bases

All digital data can ultimately be represented in binary, but hexadecimal simplifies representations by using single digits for groups of four binary digits.
The claim that there is a limit to what binary can represent before switching to hexadecimal is incorrect.

Number Comparison

The correct order of representation from least to greatest for BIN: 1110, DEC: 13, HEX: F is DEC: 13, BIN: 1110, HEX: F.

Unique ID Representation

To ensure each new student at a school receives a unique ID, one effective method is to add a bit to the current 8-bit studentID, thereby doubling the IDs capacity.

Website Loading Dynamics

A scenario where a website loads immediately but images appear slowly indicates low bandwidth but low latency.

Bits for Number Representation

To represent 512 different numbers, 9 bits are needed (as 2^9 = 512).

ASCII and Hexadecimal

ASCII utilizes a numeric value to represent characters. For instance, the uppercase letter "G" corresponds to the decimal value 71.

Description

This set of flashcards is designed to help students prepare for the APCSP exam by testing their understanding of how digital data is represented in computers. Explore various explanations related to binary representation and deepen your knowledge in computer science concepts. Perfect for quick revisions and practice before the test.