WorksheetsAQA A Level Computer Science Quiz
Total questions: 20
Worksheet time: 10mins
Which of the following best describes the range of decimal values that can be represented by 8 bits using Two’s Complement?
0 to 255
-127 to +128
-128 to +127
-256 to +255
In a floating-point binary number, what is the effect of increasing the number of bits allocated to the mantissa while keeping the total number of bits the same?
Increases the range of numbers that can be represented.
Increases the precision of the numbers.
Increases both range and precision.
Decreases the precision but increases the range.
Which of the following is true regarding a 'normalized' floating-point number in binary?
The exponent is always 0.
The first two bits of the mantissa must be different (01 for positive, 10 for negative).
The decimal point is always placed after the rightmost bit.
The mantissa always starts with a 1.
A bitmap image has a resolution of 100 x 100 pixels and a colour depth of 16 bits. What is the minimum file size in bits (ignoring metadata)?
10,000 bits
160,000 bits
1,600,000 bits
20,000 bits
According to the Nyquist theorem, to accurately reconstruct a sound wave with a maximum frequency of 10,000 Hz, the sampling rate must be at least:
5,000 Hz
10,000 Hz
20,000 Hz
44,100 Hz
Which of the following statements about Vector Graphics is FALSE?
They are defined by mathematical formulas and geometry.
They lose quality and become pixelated when scaled up.
They typically require less storage space for simple geometric shapes compared to bitmaps.
Specifically useful for logos and fonts.
What is the value of the binary number `1000 0000` if it is interpreted as an unsigned integer, and what is it if interpreted as a Two’s Complement signed integer?
Unsigned: 128, Signed: -128
Unsigned: 128, Signed: -0
Unsigned: 128, Signed: 128
Unsigned: 256, Signed: -127
Which character set was originally a 7-bit code allowing for 128 characters?
Unicode
UTF-8
EBCDIC
ASCII
In the context of data units, how many bytes are in one Kibibyte (KiB)?
1000 bytes
1024 bytes
8000 bytes
1024 bits
Run Length Encoding (RLE) is most effective for compressing which type of data?
Text files with complex vocabulary.
Photographs with many changing colours and gradients.
Simple images with long sequences of the same colour pixels.
Audio files with high variance in amplitude.
When adding two positive integers in 8-bit binary, an overflow error occurs if:
The result is negative.
The result requires 9 bits to represent.
The carry bit into the MSB is 0.
The numbers are odd.
Which of the following best describes 'Dictionary-based compression'?
It removes frequencies that are outside human hearing range.
It replaces repeated sequences of data with short tokens or references.
It averages the colour of adjacent pixels to save space.
It converts the file into a lower bit rate.
What is the primary disadvantage of using Fixed Point binary representation compared to Floating Point?
It is slower for the CPU to process.
It cannot represent negative numbers.
It has a very limited range of values it can represent.
It introduces more rounding errors for all numbers.
In a MIDI (Musical Instrument Digital Interface) file, which of the following is NOT stored?
The pitch of the note.
The duration of the note.
The actual sampled sound wave of the instrument.
The volume (velocity) of the note.
An Analogue to Digital Converter (ADC) works by:
Measuring the amplitude of the analogue wave at regular intervals.
Drawing the wave as a vector path.
Compressing the wave into MP3 format immediately.
Converting binary data back into voltage changes.
What is the purpose of a Parity Bit?
To encrypt the data being sent.
To allow the receiver to detect if a single bit has flipped during transmission.
To correct multiple errors in a data stream automatically.
To synchronize the clock speeds of the sender and receiver.
Which of the following is an example of Lossy Compression?
ZIP
PNG
JPEG
FLAC
How do you calculate the 'Sound File Size' (in bits)?
Sample Rate x Duration
Sample Rate x Resolution x Duration x Number of Channels
Resolution x Duration x 2
(Sample Rate / 2) x Resolution
In the Hexadecimal system, the number `1A` represents what decimal value?
110
26
16
31
'Majority Voting' is an error correction method that involves:
Sending every bit three times and accepting the value that appears most often.
Checking the parity bit of every byte.
Using a checksum algorithm like MD5.
Asking the user to verify the data manually.
