AP CSP Standard 4

Which of the following is a benefit that online shopping websites provide over brick and mortar stores?

• Users can try out an item before they buy it

• Users can easily pay with cash in person

• Users can easily see product reviews and determine if an item has been satisfactory for a large number of people

• There is no wait time between purchasing an item and having access to it

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

• Hexadecimal (Base 16)

• Octal (Base 8)

• Binary (Base 2)

• Decimal (Base 10)

How many different values can be represented using 4 bits?

• 32 different values

• 16 different values

• 8 different values

• 4 different values

Which of the following is a true statement about data compression?

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

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

• Regardless of the compression technique being used, once a data file is compressed, it cannot be restored back to its original state.

• Data compression is only useful for files being transmitted over the Internet.

Jennifer is transferring photos from her camera to her computer. She 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?

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

• The saved image files were not compressed properly.

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

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

An online store uses 8-bit binary values to identify each unique item for sale. The store plans to increase number of items it sells and is considering changing to 9-bit binary values.

Which of the following best describes the result of using 9-bit values instead of 8-bit values?

• 2^9 times as many items can be uniquely identified

• 2 times as many items can be uniquely identified

• 9 more items can be uniquely identified

• 2 more items can be uniquely identified

A computer program uses 3 bits to represent integers. When the program adds the decimal (base 10) numbers 6 and 2, the result is 0. Which of the following is the best explanation for this result?

• The result was affected by lossy data compression.

• An off-by-one error occurred.

• A round-off error occurred.

• An overflow error occurred.

The RGB encoding scheme encodes a color using 24 bit sequences. The first 8 bits encode the amount of red in the color, the next 8 bits encode the amount of green in the color, and the last 8 bits encode the amount of blue in the color.

Which of the following is a true statement about the color encoded by this binary sequence:

1110 1001

0111 1100

0000 1111

• This color has no blue in it.

• This color is mostly blue.

• This color is mostly green.

• This color is mostly red.

Suppose we have the following function that modifies a pixel and returns the result:

var RED = 0;

var GREEN = 1;

var BLUE = 2;

function filter(pixel) {

pixel[RED] = 255 - pixel[RED];

pixel[GREEN] = 255 - pixel[GREEN];

pixel[BLUE] = 255 - pixel[BLUE];

return pixel;

}

Which of the following best describes the result of applying this filter to every pixel in the image?

• The image will be inverted, bright pixels will become dark and dark pixels will become bright.

• The image will look slightly brighter.

• The image will look slightly darker.

• The image will be grayscaled to a black and white image.

What is data abstraction?

• Filtering data to gain new knowledge

• The process of simplifying complicated data into manageable chunks

• Storing data in as little space as possible

• Manipulating data to create something new