paper 2 exam q Flashcards
A minimum color depth of two bits is needed to store the image. Explain how the image in can be represented as a bitmap. (3 marks)
The pixels are stored consecutively (1)
each color could be represented by a unique 2-bit pattern (1)
. the bitmap will need the width and height included (1)
Give one reason why a CPU with two cores might perform faster than an equivalent CPU with only one core. (1)
The processor with two cores may be able to process two instructions simultaneously (1)
Give one example of a type of volatile memory in a computer system (1 mark)
RAM
Explain why secondary storage is required in a computer system. (2 marks)
For Storing data / files (1) using non-volatile storage (1)
Explain the role of main memory in the execute stage of the Fetch-Execute cycle.(2 marks)
Data required by an instruction may be fetched from main memory (1)
Result of instruction may be stored in main memory (2)
State one advantage of writing programs in assembly language instead of a high-level language. (1 marks)
Programs written in assembly language run faster (1)
Describe two differences between a PAN and a WAN (2 marks)
PAN centered round a person (1) PAN and WAN use different protocols (2)
State two differences between a bus topology and a star topology (2 marks)
A bus network has all computers connected to a backbone (1)
All devices / computers on a bus network see all data transmitted (1)
What are 2 benefits of relational databases? (2)
Redundant data is less likely to be stored (1)
There are less likely to be data inconsistences (1)
State 4 functions of an operation system (4)
Process management (1)
Memory management (1)
Applications management (1)
Security management (1)
State 2 statements about code written in low-level language than high-level language. (2 marks)
Code is not translated using a compiler (1)
Code can directly manipulate computer registers (2)
State the purpose of an assembler (1)
To translate assembly language into machine code (1)
Explain how an interpreter works (4 marks)
-they don’t produce machine code so program needs to be translated every execution (1)
-call machine code subroutines in their own code to carry out commands (1)
-they translate line at a time which is then executed (1)
-if a runtime error is found then interpreter stops (1)
State 2 reasons why computers have more RAM then cache memory (2)
RAM is cheaper per byte (1)
Capacity of cache cannot store both data and programs (1)
State 2 advantages of using cloud storage over local storage (2)
Enables user to access data from more places (1)
Enables user to share data more easily with users (1)
Explain why solid-state storage is not fitted into every computer (2)
SSDs are expensive / higher cost per gigabyte (1)
SSDs have lower capacity (1)
State 1 disadvantage of higher sample sound resolution (1)
Higher file size / sound files will take longer to download / uses more memory processing when recording (1)
State 2 issues with only using username and password when authenticating a user (2 marks)
Weak passwords are easily guessed(1)
Username/passwords may have appeared in a data leak (1)
describe one security measure that could be used in addition to a password that could be used to check authenticity (2)
-biometrics; compare data to user’s unique biometric data (1)
-authenticator app on phone; generates a code that user can input to log-in (1)
State 2 reasons why automatic software updates provide better security than manual software updates (2)
-user may forget to do updates manually (1)
-automatic updates mean that computer is protected more quickly (1)
Sate 2 reasons why data is compressed (2)
-to reduce file size (1)
-to make it faster to transmit (1)
Define the term relational data base (2)
Database with multiple tables (1) that are linked together (1)
state 1 benefit of using relational databases (1)
Reduces data inconsistency
explain what effects increasing the sample rate would have on the recording (2)
File size would increase (1)
The more samples per second, the more accurate the sound is (1)
State 2 functions of an operating system (2)
Application management
Process management
State 2 correct facts about RAM (2)
Used for main memory (1)
it is volatile memory (1)
Explain how clock speed affects CPU performance (2)
The more pulses per second, the more fetch-execute cycles (1)
Each instruction starts on a clock pulse (1)
Explain how the number of processer cores affects CPU performance (2)
Affects the number of instructions that can be executed simultaneously (1)
Each processor core can fetch and execute its own instructions (1)
Explain how cache size affects the CPU performance (2)
Instructions take less time to transfer to the processor from cache (1)
Because cache is held closer to the processor (1)
Define the term computer network (2)
2 or more computers (1) Connected together (1)
Explain how a firewall can be used to improve the security of a network (2)
Acts as a barrier between a computer and external devices (1)
Inspects incoming and outgoing packets of data (1)
Describe 2 differences between an embedded-system and a non-embedded system (2)
Embedded systems have specific purpose, non-embedded have a general purpose (1)
Embedded-systems have small amount of memory compared to non-embedded (1)
Give 3 examples of when it would be suitable to use a CAPTCHA system (3)
Account registration (1)
Account access (1)
Online voting system (1)
describe the role of the clock in the CPU
Regulates the timing and speed of (computer) operations // sends out a regular electronic pulse / timing signal;
describe the role of the control unit in the CPU
Coordinates the actions of the CPU // decodes instructions // sends control signals; A. controls the flow of data through the CPU
describe the role of the register in the CPU
Holds data used when executing an instruction // holds the result of executing an instruction // holds an instruction (CIR) // holds a memory address (MAR);
