IGCSE Quiz on Data Representation (Text, Sound, Images)

Which code is most commonly used to represent characters in a computer?

• ASCII

• JPEG

• MP3

• RGB

How many bits are used in standard ASCII?

• 7 bits

• 8 bits

• 16 bits

• 32 bits

Unicode is used instead of ASCII because:

• It uses fewer bits

• It can represent characters from many languages

• It is faster to process

• It is used only for images

In digital sound recording, the process of measuring the amplitude at regular intervals is called:

• Encoding

• Sampling

• Compression

• Quantization

Which factor does not affect the quality of a digital sound file?

• Sampling rate

• Bit depth

• File compression type

• Monitor refresh rate

A sound file is recorded with a sampling rate of 44,100 Hz. What does this mean?

• 44,100 bits are stored per second

• 44,100 samples are taken per second

• 44,100 bytes are stored per second

• 44,100 waveforms are played per second

In bitmap images, what does each pixel store?

• Character codes

• Colour values

• Sound waves

• File names

Which is an advantage of vector graphics over bitmap graphics?

• Higher colour depth

• Smaller file size for simple images

• More realistic photographs

• Stored as pixels

An image is 200 pixels wide and 100 pixels tall, with 24 bits per pixel. What is the uncompressed file size?

• 2,400 bytes

• 480,000 bytes

• 600,000 bytes

• 2,400,000 bytes

Which of the following best describes 'bit depth' in sound recording?

• The number of times sound is sampled per second

• The number of bits used to store each sample

• The size of the sound file in bytes

• The total number of samples in the recording