AP Computer Science Principles Unit 1

Select the answer that lists the units of bytes in ascending order (from smallest to largest)

• gigabyte, megabyte, terabyte

• megabyte, terabyte, kilobyte

• gigabyte, terabyte, megabyte

• kilobyte, gigabyte, terabyte

8 bits is enough to represent 256 different numbers. How many total bits do you need to represent 512 (twice as many) numbers?

• 9 Bits

• 10 Bits

• 16 Bits

• 17 Bits

Approximately how much bigger (how many more bytes) is a megabyte than a kilobyte?

• 1,000 times bigger

• 100,000 times bigger

• 1,000,000 times bigger

• 1,000,000,000 times bigger

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

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.

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 when compared to other number systems (for example, the decimal number system)

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

Consider the following three binary numbers:

01010 010000 1110

Which of the following lists the numbers in order from least to greatest?

• 010000, 1110, 01010

• 01010, 1110, 010000

• 01010, 010000, 1110

• 1110, 01010, 010000

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

• 0010

• 1010

• 0110

• 0101

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.

• Latency is the amount of data (measured in bits) that can be sent in a fixed amount of time.

• Digital data can only be transmitted between two devices when they are physically connected to one another (for example by a copper wire)

• Two devices must communicate using the same bit-rate to successfully send and receive digital data.

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