Paper 2 CS · UNIT 05 · MOCK TEST

System Software and Operating System — Mock Test 5

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

0 / 25 answered 00:00

Q1.

Which of the following statements about the cron daemon in a UNIX operating system is NOT correct?

A(A) cron is the standard tool for running commands on a predetermined schedule. B(B) It starts when the system boots and keeps running as long as the system stays up. C(C) cron reads configuration files (crontabs) that list command lines together with the times at which they should be invoked. D(D) Crontabs for individual users are not stored.

Q2.

In UNIX, which single command creates the directory "PIS" together with its two subdirectories "progs" and "data" (i.e. PIS/progs and PIS/data), all newly created in one invocation?

A(A) mkdir PIS/progs PIS/data PIS B(B) mkdir PIS progs data C(C) mkdir PIS PIS/progs PIS/data D(D) mkdir PIS/progs data

Q3. Match List - I with List - II.

List - I	List - II
A. Latency	I. number of tasks completed in a given time period
B. Delay	II. causes the current activity to be deferred
C. Throughput	III. time elapsed before next activity starts
D. Interrupt	IV. time to complete a single task

Choose the correct answer from the options given below:

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

Q4. In Rate Monotonic scheduling, if a task has a period of 80 ms and an execution time of 55 ms, then its processor utilization and task rate will be

A0.69, 12.5 Hz B0.58, 12.3 Hz C0.48, 11.4 Hz D0.38, 10.5 Hz

Q5. Match the LIST-I with LIST-II.

LIST-I	LIST-II
A. Disk Scheduling	I. Round Robin
B. Batch Processing	II. SCAN
C. Time Sharing	III. LIFO
D. Interrupt Processing	IV. FIFO

Choose the correct answer from the options given below:

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

Q6. For the reference string: (given that number of frames is 3)
7 0 1 2 0 3 0 4 2 3 0 3 2 1 2 0 1 7 0 1
for the optimal page replacement algorithm, which of the following will represent the hit ratio?

A11/20 B10/20 C9/20 D12/20

Q7. Which of the following is not an interprocessor communication mechanism in UNIX?

APipes BMessages CShared memory DSemaphore

Q8. In disk scheduling example, suppose the disk tracks are numbered from 0 to 49. Head is presently positioned at track 15 and requests for tracks 4, 40, 11, 35, 7 and 14 have arrived (in that order). It takes 1 ms to travel from one track to the next adjacent track. Following disk scheduling algorithms are to be executed and total time traversed is to be recorded (in ms) in ascending order (assume arm-movement toward high numbered request first, wherever needed):
A. FCFS
B. LOOK
C. SSTF
D. SCAN
Choose the correct answer from the options given below:

AC, B, D, A BB, A, C, D CC, D, B, A DD, B, C, A

Q9. Following is not the feature/characteristic of Linked-List allocation of Files in a File system:

ANo space is lost in this allocation to disk fragmentation (except for internal fragmentation in the last block) BReading of files or accessing them in Random access is very fast CAmount of data stored in a block is not in powers of 2 as pointer takes few bytes DThe disadvantages of Linked-List allocation can be overcome by using a Table in main memory called FAT

Q10. Match List - I with List - II.

List - I	List - II
A. Macros	I. Converts high level code to object (Machine) code
B. Assembler	II. Used for code Expansion
C. Loader	III. Used to translate assembly language code to object code
D. Compiler	IV. Used to allocate memory and relocate program in memory

Choose the correct answer from the options given below:

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

Q11. Once the process is allocated CPU and executing, which of the following events could NOT occur?
A. The process could issue an I/O request and then be placed in the Ready Queue
B. The process could create new subprocesses & wait for the termination of the subprocesses
C. The time slice of the process expires and it may join the waiting queue
D. The process is forcibly removed from the CPU and is put in the Waiting queue due to arrival of an interrupt
Choose the correct answer from the options given below:

AB Only BD Only CA and C Only DA, C and D Only

Q12. What shall be the average waiting time per process if we know that 10 processes (on average) arrive every second and there are normally 20 processes in the queue?

A03 seconds B02 seconds C18 seconds D09 seconds

Q13. Which of the following shows the correct hierarchy of a layered file system in an operating system?
A. Logical File System
B. File Organization Module
C. Basic File System
D. I/O Control
E. Application Programs
Choose the correct answer from the options given below:

AA → B → D → C → E BD → E → C → A → B CE → A → B → C → D DE → C → B → A → D

Q14. Consider the following interrupt protection levels in Linux, and arrange them in the increasing order of their priorities.
A. User-Mode Programs (Preemptible)
B. Bottom Half Interrupt Handlers
C. Top Half Interrupt Handlers
D. Kernel System Service Routines (Preemptible)
Choose the correct answer from the options given below:

AB → A → C → D BC → B → A → D CC → A → B → D DA → D → B → C

Q15. Match List I with List II

List I	List II
A. Clustered Page Table	I. Generally considered inappropriate for 64 bit architectures.
B. Hierarchical Page Table	II. Has only one entry for each real page (or frame) of memory.
C. Segmentation	III. Useful for sparse address spaces.
D. Inverted Page Table	IV. Supports a user view of the system.

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

Q16. Identify the correct statement(s) from the following with respect to Spinlock Semaphores
A. The name refers to busy waiting semaphores.
B. They are not useful when the locks are to be held for a short duration of time.
C. It may require multiple context switches when a process waits on a lock.
D. They are often employed on Uniprocessor systems.
Choose the correct answer from the options given below:

AA Only BD Only CB, D Only DA, C and D Only

Q17. What is the total swap time (swap in + swap out) in a system for a 15 MB process with a transfer rate of 30 MBps? Given that there is an average latency of 12 ms, however no head seeks are involved.

A1.024 sec B1.00 sec C0.512 sec D12 sec

Q18. Match List I with List II

List I	List II
A. RAID Level 2	I. Block interleaved distributed parity
B. RAID Level 3	II. Also known as P+Q redundancy scheme
C. RAID Level 5	III. Bit interleaved parity
D. RAID Level 6	IV. Also known as memory style error correcting code organization

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

Q19. Consider the following table about processes, their burst time and arrival time. Which process shall finish second last as per the respective Gantt charts for non-preemptive SJF and Round Robin (time quantum = 10) scheduling methods?

Process	Burst Time	Arrival Time
P1	9	0
P2	30	0
P3	4	0
P4	8	2
P5	11	6

ASJF: P4; RR: P4 BSJF: P5; RR: P4 CSJF: P4; RR: P3 DSJF: P5; RR: P5

Q20. Which of the following statements is correct for Pthreads?

AIt refers to POSIX standard (IEEE 1002.1c) BThis standard defines API for thread creation only CThis is a specification only for thread behavior and not its implementation DOperating systems like Solaris, Linux, Mac OS X, except Tru64 UNIX, implement Pthreads