Which of the following highly uses the concept of an array?
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Correct answer: (C) Spatial locality
Explanation
Spatial locality relies on elements being stored in contiguous memory, which is exactly how arrays are laid out.
BPSC TRE · Computer Science
Operating Systems Previous Year Questions
14 Operating Systems (Computer Science) questions asked in BPSC TRE previous year papers, each with the correct answer and explanation. Read them free on UTpaper, or attempt the full papers as timed online tests.
- 14 questions
- Official answer key
- Free
Other Computer Science topics
Which of the following is correct for Digital Circuits?
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Correct answer: (E) None of the above
Explanation
None of the statements fit digital circuits: they use discrete (0/1) signals rather than analog or continuous voltage levels, and they are well suited to high-speed operation.
Which of the following is NOT a memory management technique used by operating systems?
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Correct answer: (C) Fragmentation
Explanation
Paging and segmentation are memory management techniques. Fragmentation is a problem (wasted memory) they have to deal with, not a technique.
Which of the following is a file system commonly used in operating systems?
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Correct answer: (D) More than one of the above
Explanation
NTFS (Windows), FAT32 (Windows and removable media) and HFS+ (macOS) are all common file systems, so more than one option is correct.
What is a page in paging?
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Correct answer: (A) A fixed-size block of virtual memory
Explanation
A page is a fixed-size block of the logical (virtual) address space. The matching fixed-size block of physical memory is called a frame.
What is a segment base in segmentation?
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Correct answer: (A) The starting address of a segment in physical memory
Explanation
The segment base is the starting physical address where the segment is placed in memory, and the limit gives its length.
What causes thrashing to occur?
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Correct answer: (A) Excessive paging activity
Explanation
Thrashing happens when processes do not have enough frames, so pages are swapped in and out constantly. The CPU then spends more time paging than executing.
Consider a system with a total physical memory of 8 GB and total virtual memory of 16 GB. If the system is using 6 GB of physical memory and 10 GB of virtual memory, how much memory is being swapped out?
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Correct answer: (A) 2 GB
Explanation
Official BPSC final answer key: (A). Note: many solutions take 10 GB used − 6 GB physical = 4 GB swapped out, option (B).
Consider a disk queue with requests for I/O to blocks on cylinders. 98 183 37 122 14 124 65 67 considering FCFS (First Come First Served) scheduling, the total number of head movements is, if the disk head is initially at 53 is?
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Correct answer: (A) 640
Explanation
Head movements: 53→98 (45), 183 (85), 37 (146), 122 (85), 14 (108), 124 (110), 65 (59), 67 (2). The total is 640 cylinders.
Thread shares with other threads belonging to the same process its
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Correct answer: (C) code section and data section
Explanation
Threads of the same process share the code section, the data section and OS resources such as open files. Each thread has its own thread ID, program counter, registers and stack.
What is the purpose of a software prototype?
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Correct answer: (E) None of the above
Explanation
A prototype is an early working model built to understand and refine user requirements through feedback. It is not the final version, does not replace documentation, and is not mainly meant to speed up development.
What will be the output of the following C++ code?
#include<iostream>
using namespace std;
long factorial (long a)
{
if (a>1)
return (a * factorial (a+1));
else
return(1);
}
int main( )
{
long num = 3;
cout <<num<<"!="<<factorial (num);
return 0;
}
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Correct answer: (C) Segmentation fault
Explanation
factorial(a + 1) makes the argument grow (3, 4, 5, ...), so a > 1 is never false. The recursion never ends, the stack overflows, and the program crashes with a segmentation fault.
Which of the following is not an operating system?
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Correct answer: (C) Oracle
Explanation
Oracle is a database management system (RDBMS), not an operating system. Linux and Windows are operating systems.
A software that runs on a computer hardware and serves as a platform for other softwares to run is called
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Correct answer: (B) operating system
Explanation
An operating system runs directly on the hardware, manages its resources and provides the platform on which other software runs. System software is a wider category that also includes utilities and translators.
How to use these BPSC TRE Computer Science questions
Every question here was asked in a real BPSC TRE paper; the paper and shift are shown on the card, and the number opens the question on its own page. Try each one before tapping Show answer, then attempt the full BPSC TRE papers as timed tests to check your speed under exam conditions.