AP CSP Code.org Unit 1

Which of the following best describes how computing devices represent information?

• A computer will either represent information as bits or bytes but not both

• A computer represents data as a byte which is either a 0 or a 1

• A computer represents data as bits which is either a 0 or a 1

• A computer represents information as bits which contain 8 bytes.

Which of the following is true about how analog data is converted to digital data?

• The digital version is a representation of the analog, but cannot contain all of the details.

• To make the digital version be a more accurate representation of the analog data, the process should use fewer bits to represent each sample.

• A longer interval between measured samples means more details will be captured in the conversion from analog to digital.

• The digital version contains all of the details of the analog data, as long as enough storage capacity is available.

How many bits are in two bytes of data?

• 4

• 8

• 12

• 16

The binary number 1001 is equal to what in decimal?

• 1,001

• 17

• 8

• 9

The number 43, when represented in binary is

• 0100 0011

• 1010 1101

• 0010 1011

• 0011 0001

A computer program is using 4 bits to represent an integer. When the program adds the decimal numbers 10 and 6, the result is 0000. Which of the following describe the result? (Select all that apply)

• The number 16 in decimal is 0000 in binary.

• An overflow error occurred.

• a roundoff error occurred.

• You cannot represent the number 16 with 4 bits.

A computer uses 3 bits of data to represent a number. What is the smallest number that would cause an overflow error in this situation?

• 4

• 7

• 8

• 9

ASCII is an abstraction because

• it allows the user to know the binary code for each character.

• the user can type letters and other characters without knowing the binary code assigned to them.

• it helps the user convert the decimal representation of a letter to the binary representation for the letter.

• the user can read a binary message and translate it into characters.

Which of the following statements about sampling is incorrect?

• Sampling is a process that can be used to compress an image.

• Sampling is a process for turning an analog image into a digital image.

• When smaller samples are used, the resulting file will require fewer bytes.

• Each pixel of the analog image is coded as one color, and cannot be more than one color.

What is the difference between Lossy and Lossless compression?

• With Lossy compression, none of the data is lost.

• With Lossless compression, a file cannot be decompressed to its original state.

• Lossless compression will usually reduce a file size less than Lossy compression.

• Lossy compression is reversible.