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Paper 2 CS · UNIT 05 · MOCK TEST

System Software and Operating System — Mock Test 6

25 questions · about 30 minutes. Press End Mock any time to see your score and the correct answers.

0 / 25 answered 00:00

Q1. Consider the following disk-scheduling movement and identify the algorithm it represents. Request queue: 84, 125, 11, 36, 170, 20, 172, 45 (cylinders 0–199). The head starts at cylinder 28 and services 36 → 45 → 84 → 125 → 170 → 172 moving towards higher cylinders, then jumps directly back to 11 (without going to 199 or 0) and services 11 → 20.

ASSTF BSCAN CC-SCAN DC-LOOK

Q2. Match List I with List II

List I	List II
A. RAID level 1	I. Bit-interleaved parity organization
B. RAID level 2	II. Disk mirroring
C. RAID level 3	III. Block-interleaved parity organization
D. RAID level 4	IV. ECC organization

AA-II, B-I, C-IV, D-III BA-II, B-IV, C-I, D-III CA-III, B-IV, C-I, D-II DA-IV, B-III, C-II, D-I

Q3. If the virtual memory size is 32 MB and the physical memory size is 4 MB with a page size of 2 KB, calculate the number of frames available in physical memory.

A1024 B2048 C3072 D4096

Q4. Which of the following does NOT interrupt a running process?

ADevice BTimer CScheduler DPower Failure

Q5. Given the following processes with their burst times and priorities (lower number indicates higher priority), all arriving at time 0, what is the average waiting time using the (non-preemptive) priority scheduling algorithm?

Process	Burst Time	Priority
P1	10	3
P2	1	1
P3	2	4
P4	1	5
P5	5	2

A9.2 B6.8 C7.6 D8.2

Directions (Q96–100): Consider the following set of processes with arrival time and CPU burst time given in milliseconds (ms):

Process	Arrival Time	Burst Time
P1	0	5
P2	2	3
P3	2	2
P4	5	3
P5	6	1

Q6. Calculate the average response time for these processes with the non-preemptive priority scheduling algorithm. Priorities are as follows; consider that all the processes arrive at time 0 (low numbers represent high priority).

Process	Burst Time	Priority
P1	5	3
P2	3	1
P3	2	5
P4	3	4
P5	1	2

A5.6 ms B5.2 ms C4.7 ms D3.8 ms

Directions (Q96–100): Consider the following set of processes with arrival time and CPU burst time given in milliseconds (ms):

Process	Arrival Time	Burst Time
P1	0	5
P2	2	3
P3	2	2
P4	5	3
P5	6	1

Q7. Find the average weighted turnaround time for these processes using the Highest Response Ratio Next (HRN) algorithm.

A3.2 ms B2.834 ms C1.632 ms D6.721 ms

Directions (Q96–100): Consider the following set of processes with arrival time and CPU burst time given in milliseconds (ms):

Process	Arrival Time	Burst Time
P1	0	5
P2	2	3
P3	2	2
P4	5	3
P5	6	1

Q8. What is the average turnaround time for these processes with the First Come First Serve (FCFS) scheduling algorithm?

A5.3 ms B6.4 ms C7.0 ms D8.2 ms

Directions (Q96–100): Consider the following set of processes with arrival time and CPU burst time given in milliseconds (ms):

Process	Arrival Time	Burst Time
P1	0	5
P2	2	3
P3	2	2
P4	5	3
P5	6	1

Q9. What is the average waiting time for these processes with non-preemptive Shortest Job First (SJF) scheduling?

A3.0 ms B2.1 ms C4.6 ms D3.2 ms

Directions (Q96–100): Consider the following set of processes with arrival time and CPU burst time given in milliseconds (ms):

Process	Arrival Time	Burst Time
P1	0	5
P2	2	3
P3	2	2
P4	5	3
P5	6	1

Q10. When we apply the Shortest Job First (SJF) scheduling algorithm, process P2 faces partial starvation and waits a longer time to execute. Which one of the following algorithms addresses this problem?

ARound Robin BPriority CHighest Response Ratio Next DLeast Completed Next

Q11. Which of the following statements are TRUE about mutual exclusion in concurrent programming?
(A) Mutual exclusion ensures that only one process can be in a critical section at any given time.
(B) Mutual exclusion is designed to prevent conflicts and ensure that only one process can access shared resources at a time.
(C) Mutual exclusion can use various algorithms to ensure that processes do not enter the critical section simultaneously.
(D) Mutual exclusion allows multiple processes to access the critical section simultaneously to improve performance.
Choose the correct answer from the options given below:

A(A), (B), (C) Only B(B), (C), (D) Only C(B), (D), (A) Only D(A), (C), (D) Only

Q12. Which of the following statements are TRUE about privileged instructions?
(A) They can only be executed by the operating system kernel and not by user applications.
(B) They are designed to perform operations that can directly affect the hardware or system state, such as I/O operations or changing memory-management settings.
(C) User applications can execute privileged instructions if they have the correct permissions set by the operating system.
(D) They are usually executed in user mode to ensure the safety and security of the system.
Choose the correct answer from the options given below:

A(A) and (B) Only B(A), (B) and (C) Only C(B) and (C) Only D(B), (C) and (D) Only

Q13. Match List I (Algorithms) with List II (Characteristics)

List I	List II
(A) First Come First Served (FCFS)	(I) Each process is assigned a priority.
(B) Shortest Job First (SJF)	(II) Ensures fair allocation of CPU time by assigning a time slice.
(C) Round Robin (RR)	(III) Processes are executed in the order they arrive.
(D) Priority Scheduling	(IV) Selects the process with the smallest next burst time.

A(A)-(II), (B)-(III), (C)-(IV), (D)-(I) B(A)-(II), (B)-(IV), (C)-(III), (D)-(I) C(A)-(III), (B)-(IV), (C)-(II), (D)-(I) D(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

Q14. Match List I (operating system concepts) with List II (characteristics)

List I	List II
(A) Paging	(I) Evicts least recently used page
(B) LRU (Least Recently Used)	(II) Extends physical memory
(C) C-SCAN	(III) Logical to physical mapping
(D) Virtual Memory	(IV) Circular disk access

A(A)-(III), (B)-(IV), (C)-(I), (D)-(II) B(A)-(III), (B)-(I), (C)-(IV), (D)-(II) C(A)-(I), (B)-(III), (C)-(IV), (D)-(II) D(A)-(I), (B)-(IV), (C)-(III), (D)-(II)

Q15. Which of the following statements are TRUE about the Process Control Block (PCB)?
(A) The PCB contains information about the process state, such as whether it is running, waiting or terminated.
(B) The PCB includes the program code and data segments of the process.
(C) The PCB stores the process's memory-management information, such as page tables and segment tables.
(D) The PCB is used to track process scheduling information and CPU registers for process execution.
Choose the correct answer from the options given below:

A(A), (B) and (C) Only B(B), (C) and (D) Only C(A), (C) and (D) Only D(A) and (B) Only

Directions (Q96–100): The Banker's Algorithm is a deadlock-avoidance method in operating systems, designed to facilitate resource allocation without causing deadlock. It maintains information about the maximum resources each process may require, the currently allocated resources and the available resources in the system. The algorithm checks each resource request to determine whether granting it would leave the system in a safe state, meaning that there is always a sequence in which all processes can complete their execution without getting stuck due to resource unavailability. Each process must specify its maximum demand for each resource type before it starts execution. When a process requests additional resources, the algorithm checks if granting the request will keep the system in a safe state. If so, the resources are allocated; otherwise the process must wait until its request can be safely fulfilled.

Q16. Which of the following is NOT a requirement for the Banker's algorithm to grant a resource request?

AThe requested resources must be available. BThe system must be in a safe state after granting the request. CThe request must not exceed the maximum resources the process can request. DThe process must be the only one requesting resources.

Directions (Q96–100): The Banker's Algorithm is a deadlock-avoidance method in operating systems, designed to facilitate resource allocation without causing deadlock. It maintains information about the maximum resources each process may require, the currently allocated resources and the available resources in the system. The algorithm checks each resource request to determine whether granting it would leave the system in a safe state, meaning that there is always a sequence in which all processes can complete their execution without getting stuck due to resource unavailability. Each process must specify its maximum demand for each resource type before it starts execution. When a process requests additional resources, the algorithm checks if granting the request will keep the system in a safe state. If so, the resources are allocated; otherwise the process must wait until its request can be safely fulfilled.

Q17. Which data structures does the Banker's Algorithm use to maintain the state of available, maximum and allocated resources?

APriority Queue BHash table CWait-for Graph DMatrices and Vectors

Directions (Q96–100): The Banker's Algorithm is a deadlock-avoidance method in operating systems, designed to facilitate resource allocation without causing deadlock. It maintains information about the maximum resources each process may require, the currently allocated resources and the available resources in the system. The algorithm checks each resource request to determine whether granting it would leave the system in a safe state, meaning that there is always a sequence in which all processes can complete their execution without getting stuck due to resource unavailability. Each process must specify its maximum demand for each resource type before it starts execution. When a process requests additional resources, the algorithm checks if granting the request will keep the system in a safe state. If so, the resources are allocated; otherwise the process must wait until its request can be safely fulfilled.

Q18. What is the significance of the Banker's algorithm in terms of resource management?

AIt ensures that all processes can finish their execution without deadlock. BIt eliminates the need for processes to request resources. CIt accelerates the execution of critical sections in processes. DIt minimizes the number of context switches between processes.

Directions (Q96–100): The Banker's Algorithm is a deadlock-avoidance method in operating systems, designed to facilitate resource allocation without causing deadlock. It maintains information about the maximum resources each process may require, the currently allocated resources and the available resources in the system. The algorithm checks each resource request to determine whether granting it would leave the system in a safe state, meaning that there is always a sequence in which all processes can complete their execution without getting stuck due to resource unavailability. Each process must specify its maximum demand for each resource type before it starts execution. When a process requests additional resources, the algorithm checks if granting the request will keep the system in a safe state. If so, the resources are allocated; otherwise the process must wait until its request can be safely fulfilled.

Q19. What is the primary goal of the Banker's Algorithm?

ATo allocate resources optimally BTo prevent processes from requesting resources CTo detect and recover from deadlocks DTo maximise CPU utilization

Directions (Q96–100): The Banker's Algorithm is a deadlock-avoidance method in operating systems, designed to facilitate resource allocation without causing deadlock. It maintains information about the maximum resources each process may require, the currently allocated resources and the available resources in the system. The algorithm checks each resource request to determine whether granting it would leave the system in a safe state, meaning that there is always a sequence in which all processes can complete their execution without getting stuck due to resource unavailability. Each process must specify its maximum demand for each resource type before it starts execution. When a process requests additional resources, the algorithm checks if granting the request will keep the system in a safe state. If so, the resources are allocated; otherwise the process must wait until its request can be safely fulfilled.

Q20. What information is used to determine if a resource request can be granted?

AAvailable resources and current allocation of each process BCPU utilization of each process CNumber of processes waiting for resources DArrival time of each process

Q21. An address in main memory is called:

AVirtual address BMemory address CLogical address DPhysical address

Q22. The head of a moving-head disk with 200 tracks, numbered 0 to 199, has just finished a request at track 125 and is currently serving a request at track 143. The queue of requests in FIFO order is 86, 147, 91, 177, 94, 150, 102, 175, 130. What will be the total number of head movements required to satisfy these requests with the SCAN algorithm?

A259 cylinders B169 cylinders C154 cylinders D264 cylinders

Q23. Given 4 GB (≈ 4.3 × 10⁹ bytes) of virtual space, a typical page size of 4 KB and a page-table entry of 5 bytes, how many virtual pages would this imply, and what is the size of the whole page table?

A1075000 and 5375 KB B215000 and 40960 bytes C10750 and 10240 bytes D43000 and 1024 bytes

Q24. In Linux, where is the user password stored?

A/etc/password B/root/password C/etc/passwd D/root/passwd

Q25. Indexed (grouped) allocation is useful because:
(A) It supports both sequential and direct access.
(B) The entire block is available for data.
(C) It does not require lots of space for keeping pointers.
(D) There is no external fragmentation.
Choose the correct answer from the options given below:

A(A) Only B(B) and (C) Only C(B) Only D(A), (B) and (D) Only