Y10 Binary Data Rep Homework

What is the primary reason Unicode is preferred over ASCII for global applications?

• Unicode uses fewer bits, making it more efficient.

• Unicode can represent a wider range of characters from different languages.

• Unicode is faster to process than ASCII.

• Unicode is only used for special symbols.

Answer explanation

Unicode is preferred over ASCII because it can represent a wider range of characters from different languages, making it essential for global applications that require diverse linguistic support.

How many bits are used in the standard ASCII character set?

• 6 bits

• 7 bits

• 8 bits

• 9 bits

Answer explanation

The standard ASCII character set uses 7 bits to represent each character, allowing for 128 unique symbols. This includes control characters and printable characters, making 7 bits the correct choice.

If an image has a resolution of 1024 × 768 pixels and a colour depth of 24 bits, what is the approximate file size in bytes, excluding metadata?

• 2.25 MB

• 2.36 MB

• 2.50 MB

• 2.75 MB

Answer explanation

To calculate the file size, multiply the resolution (1024 × 768 = 786432 pixels) by the color depth (24 bits = 3 bytes). Thus, 786432 × 3 = 2359296 bytes, which is approximately 2.36 MB, making it the correct choice.

Which of the following is a characteristic of lossy compression?

• It retains all original data.

• It reduces file size by removing some data.

• It increases file size for better quality.

• It is only used for text files.

Answer explanation

Lossy compression reduces file size by removing some data, which can lead to a loss in quality. This is in contrast to lossless compression, which retains all original data.

What is the effect of increasing the bit depth in an audio file?

• The file size decreases.

• The sound quality decreases.

• The file size increases.

• The sound quality remains the same.

Answer explanation

Increasing the bit depth in an audio file enhances the dynamic range and detail of the sound, resulting in better sound quality. However, it also increases the file size due to more data being stored for each sample.

Which of the following file formats is known for using lossless compression?

• JPEG

• MP3

• PNG

• MPEG

Answer explanation

PNG is known for using lossless compression, meaning it retains all original data without quality loss. In contrast, JPEG and MP3 use lossy compression, which reduces file size at the expense of quality.

What does the term "colour depth" refer to in digital imaging?

• The number of pixels in an image.

• The number of bits used to represent each pixel's colour.

• The physical size of the image.

• The type of file format used.

Answer explanation

The term "colour depth" refers to the number of bits used to represent each pixel's colour in digital imaging. Higher colour depth allows for more colours and finer detail in images, making it the correct choice.

How is the bit rate of an audio file calculated?

• Sample rate + bit depth

• Sample rate × bit depth

• Bit depth ÷ sample rate

• Sample rate - bit depth

Answer explanation

The bit rate of an audio file is calculated by multiplying the sample rate (samples per second) by the bit depth (bits per sample). Thus, the correct choice is 'Sample rate × bit depth'.

Which of the following is a lossy compression format for audio?

• WAV

• FLAC

• MP3

• AIFF

Answer explanation

MP3 is a lossy compression format for audio, meaning it reduces file size by removing some audio data. In contrast, WAV, FLAC, and AIFF are lossless formats, preserving the original audio quality.

What is the main advantage of using a higher resolution in digital images?

• Smaller file size

• Better image quality when enlarged

• Faster processing speed

• Reduced colour depth

Answer explanation

The main advantage of using a higher resolution in digital images is that it provides better image quality when enlarged. Higher resolution means more detail, which prevents pixelation during enlargement.