CS Unit 6 Quiz Review

Which number system is used to store information digitally in a computer?

• Decimal (base 10)

• Binary (base 2)

• Octal (base 8)

• Hexadecimal (base 16)

How many different digits are used in the Hexadecimal number system?

• 2

• 10

• 8

• 16

What is the decimal value of 1101₂?

• 13₁₀

• 12₁₀

• 1.101₁₀

• 1.101₁₀

How many different values can be represented using 4 bits?

• 4 different values

• 8 different values

• 16 different values

• 32 different values

Suppose the ESPN website uses 8-bit unsigned integers to store how many points a team has scored in an NBA game.
For example:
0000 0010 represents 2 points
0000 1000 represents 8 points

What is the highest possible score the ESPN website could display?

• 256₁₀

• 255₁₀

• 11111111₁₀

• 128₁₀

A news website uses 32-bit integers to count the number of times an article has been viewed.

The website is becoming more popular, and expects some of the articles to exceed the number of views that can be represented with 32 bits. In anticipation of this, the website is planning to change to 64-bit integers for the view counter.

Which of the following best describes the result of using 64-bit integers instead of 32-bit integers?

• 2 times as many values can be represented

• 32 times as many values can be represented

• 2³² times as many values can be represented

• 32² times as many values can be represented

ASCII is a character encoding scheme that uses a numeric value to represent each character.

For example, the uppercase letter ‘G’ is represented by the binary (base 2) value 0100 0111, which is equivalent to the decimal (base 10) value 71.

A subset of characters and their corresponding ASCII values are shown in the table.

ASCII characters can also be represented by hexadecimal (base 16) numbers. According to the ASCII character encoding, which of the following characters is represented by the hexadecimal (base 16) number 6E₁₆

• n

• N

• k

• E

Refer to the ASCII table.

Which ASCII character is represented by the decimal (base 10) number 72?

• 7

• c

• r

• H

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 being used, once a data file is compressed, it cannot be restored back to its original state.

• Sending a compressed version of a file ensures that no one can read the contents of the file except for the intended recipient.

• There are trade-offs involved in choosing a compression technique for storing and transmitting data.

A student is transferring photos from her camera to her computer. The student notices that the saved photos on her computer are lower quality than the original raw photo on her camera.

Which of the following could be a possible explanation for the difference in image quality?

• The saved image files were compressed with a lossy compression technique.

• The saved image files were compressed with a lossless compression technique.

• The saved image files were not compressed properly.

• Some information is lost every time a file is saved on a computer.