Computer Science GS
2026 | Study Guide,
Practice Questions,
Answers, Rationales &
Exam Review | Complete
Ethics Study Guide
Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
,What is a Natural Number and its Symbol? Positive Integer (N)
What is a Real Number and its Symbol? Any number (R)
What is an Integer and its Symbol? Any whole number (Z)
What is a Rational Number and its Symbol? Can be represented in a Fraction (Q)
What is a Ordinal Number? Position in a list
What is a Cardinal Number? Size of list
What is Absolute Error? Difference between actual answer and estimate
What is Relative Error? absolute error/true value
How does parity bit work? (Odd/Even) Bit (1/0) is added at end of code.
Even parity - If there is an even number of 1's, 0 is added
Odd parity - If there is an even number of 1's, 1 is added
What is Majority Voting? 3 bits are sent that are the same as the original bit, the majority amount received is
taken as the original bit. 101 = 1. Good as corrects errors as well as spotting them.
What is Check digit? All numbers are added up, then the digits of the answer are added up, this is
repeated until you are left with 1 digit.
3+4+2+8 = 17
1+7 = 8
What is Bit/ Colour depth? Amount of bits used to represent all the colours of an image.
17 colours requires 5 bits.
, What is Metadata? Data about an image/ other data.
-Time, Bit depth, Size
What is Analogue data? It is infinite and represented in wave form
What is Digital data? Represented in binary, finite and can be processed by a computer
Why are ADC's used? A computer needs to process analogue signal so data needs to be converted from
Analogue to Digital.
What is Nyquist's theorem? Sound should be sampled at double the highest frequency.
What is Sampling? The process of converting Analogue signals to Digital.
-Specific readings of amplitude (Samples) are taken at regular intervals and
converted and stored in binary.
What happens when sample rate increases? - Increase in file size
- Increase in quality
What is Encryption? Converting Plaintext to Ciphertext to make it useless for anyone who intercepts it.
What is a Caeser Cipher? Moving the alphabet up and down or replacing letters with other letters.
What is a Vernam Cipher? Using a randomly generated key for both encryption and decryption. XOR gate is
used.
2026 | Study Guide,
Practice Questions,
Answers, Rationales &
Exam Review | Complete
Ethics Study Guide
Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
,What is a Natural Number and its Symbol? Positive Integer (N)
What is a Real Number and its Symbol? Any number (R)
What is an Integer and its Symbol? Any whole number (Z)
What is a Rational Number and its Symbol? Can be represented in a Fraction (Q)
What is a Ordinal Number? Position in a list
What is a Cardinal Number? Size of list
What is Absolute Error? Difference between actual answer and estimate
What is Relative Error? absolute error/true value
How does parity bit work? (Odd/Even) Bit (1/0) is added at end of code.
Even parity - If there is an even number of 1's, 0 is added
Odd parity - If there is an even number of 1's, 1 is added
What is Majority Voting? 3 bits are sent that are the same as the original bit, the majority amount received is
taken as the original bit. 101 = 1. Good as corrects errors as well as spotting them.
What is Check digit? All numbers are added up, then the digits of the answer are added up, this is
repeated until you are left with 1 digit.
3+4+2+8 = 17
1+7 = 8
What is Bit/ Colour depth? Amount of bits used to represent all the colours of an image.
17 colours requires 5 bits.
, What is Metadata? Data about an image/ other data.
-Time, Bit depth, Size
What is Analogue data? It is infinite and represented in wave form
What is Digital data? Represented in binary, finite and can be processed by a computer
Why are ADC's used? A computer needs to process analogue signal so data needs to be converted from
Analogue to Digital.
What is Nyquist's theorem? Sound should be sampled at double the highest frequency.
What is Sampling? The process of converting Analogue signals to Digital.
-Specific readings of amplitude (Samples) are taken at regular intervals and
converted and stored in binary.
What happens when sample rate increases? - Increase in file size
- Increase in quality
What is Encryption? Converting Plaintext to Ciphertext to make it useless for anyone who intercepts it.
What is a Caeser Cipher? Moving the alphabet up and down or replacing letters with other letters.
What is a Vernam Cipher? Using a randomly generated key for both encryption and decryption. XOR gate is
used.
