AS Level Computer Science chapter 5: System software MCQs with answers
By Team Megalecture · Updated 4 Nov 2026
20 exam-style questions on System software, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.
Try each one, then open the answer. These ten stay the same; the test draws new ones every time.
1. What is a benefit of Java's approach of compiling to bytecode?
A
the program never needs to be translated into machine code
B
it always runs faster than a fully compiled program would
C
the bytecode runs on any computer that has a virtual machine
D
syntax errors are only found when the program is run
Show answer
Answer: C. Bytecode is platform-independent: each type of computer has its own virtual machine, so one compiled file runs on all of them.
2. Why might a software company distribute a compiled program rather than source code to be interpreted?
A
it runs without a translator and the source code stays hidden
B
errors are reported line by line to the user as it runs
C
the same file runs on any type of processor without change
D
small changes to the program are quicker to make and test
Show answer
Answer: A. A compiled executable runs without the compiler being present and users cannot easily read or change the source code. Line-by-line error reports are a feature of interpreters.
3. How does an operating system manage peripheral devices?
A
it stores the data for each device permanently in ROM
B
it compiles a new program for each device when it starts
C
it uses device drivers and handles their interrupts
D
it defragments each device's memory at regular intervals
Show answer
Answer: C. Hardware management uses device drivers to communicate with each peripheral and responds to the interrupts they send, for example when a printer runs out of paper.
4. What does single stepping allow a programmer to do?
A
execute one statement at a time and watch its effect
B
run the whole program with only one set of test data
C
compile one module of the program at a time
D
indent each block of the code automatically
Show answer
Answer: A. Single stepping runs one line at a time, so the programmer can watch variable values change in a report window and spot where the logic goes wrong.
5. What does a disk formatter do?
A
sorts all the files on the disk into alphabetical order
B
repairs any files on the disk that have been corrupted
C
prepares a disk for use by setting up its file structure
D
makes an incremental backup of files that have changed
Show answer
Answer: C. Formatting sets up the structure the OS needs to store files and removes existing data. Repairing files is disk repair software; backups are made by back-up software.
6. What does prettyprint do in an IDE?
A
colours and indents code to make it easier to read
B
prints a formatted listing of the program on paper
C
converts the code into a flowchart for documentation
D
removes comments and blank lines to shorten the code
Show answer
Answer: A. Prettyprint colour-codes keywords, strings and comments and indents code blocks, which makes structure and mistakes easier to see.
7. Which statement about a Dynamic Link Library (DLL) is correct?
A
it is copied into every executable file when it is compiled
B
it must be rewritten for each new program that uses it
C
it is loaded at run time and can be shared by several programs
D
it can only be called by the operating system, not by apps
Show answer
Answer: C. A DLL is linked when the program runs, so one copy in memory can serve several programs and executables stay smaller. Static libraries are copied into the executable.
8. Why is defragmentation not recommended for a solid state drive?
A
location does not affect access time, and writes wear the cells
B
an SSD cannot store files that have been split into fragments
C
an SSD is defragmented automatically by the CPU at start-up
D
defragmentation would delete the files stored on an SSD
Show answer
Answer: A. An SSD has no moving head, so fragments are read as quickly as contiguous data. Flash cells can only be rewritten a limited number of times, so needless writes shorten its life.
9. Why does a computer system need an operating system?
A
to translate high-level programs into machine code
B
to store the user's files permanently when power is off
C
to increase the clock speed of the processor as needed
D
to provide an interface and manage hardware and software
Show answer
Answer: D. The OS hides the complexity of the hardware, gives the user an interface and manages resources for application programs. Translation is done by compilers and interpreters.
10. Which is a memory management task of an operating system?
A
deciding the order in which processes use the CPU
B
allocating memory to processes and keeping them apart
C
checking user names and passwords
D
organising files into folders
Show answer
Answer: B. Memory management allocates memory to each process and stops one process overwriting another's memory. Scheduling the CPU is process management.
20, each with the answer and a short explanation, across 2 topics: Operating systems, Language translators. Every chapter test draws ten of them, so you can take it many times.
Is the AS Level Computer Science chapter 5 test free?
Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.
How is the chapter test marked?
The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.
