AP CSP Unit 1 Questions

An online store uses 6-bit binary sequences to identify each unique item for sale. The store plans to increase the number of items it sells and is considering using 7-bit sequences. Which of the following best describes the result of using 7-bit sequences instead of 6-bit sequences?

• 2 more items can be uniquely identified.

• 10 more items can be uniquely identified.

• 2 times as many items can be uniquely identified.

• 10 times as many items can be uniquely identified.

A computer program uses 3 bits to represent integers. When the program adds the decimal (base 10) numbers 5 and 3, the result is 0. Which of the following is the best explanation for the result?

• An overflow error occurred.

• A round-off error occurred.

• The result was affected by lossy data compression

• The result was approximated by a floating-point representation

Which of the following is the best definition of a protocol?

• A preliminary sketch of an idea

• A set of rules governing the exchange or transmission of data between devices

• The original draft of a diplomatic document

• A physical system for sending binary information to another device

ASCII is a character-encoding scheme that uses 8 bits to represent each character. The decimal (base 10) values 65 through 90 represent the capital letters A through Z, as shown in the table below. What ASCII character is represented by the binary (base 2) number 01001010 ?

• H

• I

• J

• K

You have a coordinate grid that is 25 x 25 units. Assuming that you encode the x and y coordinate as separate numbers, what is the minimum number of bits that you will need to encode an (x, y) pair of coordinates in that space?

• 4

• 14

• 10

• 5

The term "bit" stands for which of the following?

• Binary Digit

• Binary Information Technology

• Basic Information Token

• Binary Instruction

Number systems with different bases such as binary (base-2), octal (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?

• All digital data can ultimately be represented in binary using only combinations of the digits zero and one

• The number system you use to view data has no effect on the underlying digital data

• Binary can be used to represent more complex, higher level information, including but not limited to numbers, text, and images

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

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 "97" in ASCII?

• 2 bits

• 16 bits

• 24 bits

• 7 bits

Which of the following correctly pairs the bit sending technology with the underlying system?

• Copper Wire & Electric Voltage, Radio Wave & Beam of Light, Fiber Optic Cable & Alternating Frequencies

• Copper Wire & Beam of Light, Radio Wave & Electric Voltage, Fiber Optic Cable & Alternating Frequencies

• Copper Wire & Electric Voltage, Radio Wave & Alternating Frequencies, Fiber Optic Cable & Beam of Light

• Copper Wire & Beam of Light, Radio Wave & Electric Voltage, Fiber Optic Cable & Alternating Frequencies

IP addresses are a way to identify devices connected to the internet (we'll learn more about what IP addresses are soon!). An IPv4 address is encoded in 32 bits or 4 bytes. Typically when you see an IP address it is organized as 4 separate numbers separated by periods, where each of the 4 numbers is stored in 1 byte (8 bits). With this in mind, which of the following would not be a possible IP address?

• 8.8.8.8

• 192.168.1.1

• 32.344.216.42

• 142.237.56.117