GATE CS 2021 : National Champion quiz 2 (App update required to attempt this test) for GATE & PSU CS Exams

Question 1

CPU scheduling is a process which allows one process to use the CPU while the execution of another process is on hold(waiting time) due to unavailability of any resource like I/O etc, thereby making full use of CPU. Thus the task of CPU is to maximize its Utilisation. What among the following is not true to achieve that ?

Question 2

Medium term scheduler is

Question 3

Let fork (X) be a function that creates a new process and execution of new process starts from the label X. (i.e., PC register set to X address for new process). Join ( ) will combine all the processes those can execute join ( ).
Consider the following code used for concurrency with the statements

and

Which of the following is correct precedence graph for the above code?

Question 4

A system has three processes P1, P2, P3 and three resources R1, R2, R3. There are two instances of R1, one instance of R2 and three instances of R3. P1 holds an instance of R1 and an R3 and is requesting an R2. P2 holds an R1 and an R2 and is requesting an instance of R3. P3 holds an instance of R3 and is requesting an R2. Write 0 if above scenario leads to deadlock or write 1, if deadlock does not exist.

Question 5

If there is a process of size 4MB. Given that number of pages is 512 K and page table entry is 8 bytes. Then Optimal page size so that wastage is minimum is _____KB.

Question 6

Suppose a disk has 100 cylinders numbered from 0 to 99. Initially, the disk arm is at cylinder 50, and following is the queue of disk accesses requests:

10, 63, 98, 50, 20, 35, 65.

If SSTF is used for scheduling the disk accesses, then the request for cylinder 20 is served after how many requests?

Question 7

If a software company wants to have computer network consisting of 96 hosts, then what is the best possible mask that the network administrator should choose.

Question 8

Which 3 layers does a router have?

Question 9

Which of the following statements are true?
S1: If a Privileged Instruction is executed in User Mode, then it will not be executed and will be treated as an illegal instruction
S2: To change the mode from Privileged to Non-Privileged, a Privileged Instruction is required that does not generate any interrupt.
S3: Generating any Trap Instruction is a Privileged Instruction.

Question 10

A certain telecom company 'A' has a linear bandwidth of 8000 Hz. The signal to noise ratio is 35db. The capacity of the channel would be

Question 11

Suppose Host A wants to send a large file to Host B. The path from Host A to Host B has three links, of rates R1 = 500 kbps, R2 = 2 Mbps, and R3 = 1 Mbps
1) Assuming no other traffic in the network, what is the throughput for the file transfer?
2) Suppose the file is 4 million bytes. How long will it take to transfer the file to Host B?

Question 12

Consider the following statements.

(a) The efficiency in Selective repeat protocol is , N is size of the sender window.

(b) CSMA / CD is a flow control method that is used in Ethernet.

(c) Using back off algorithm the probability of getting the collision decreases exponentially.

(d) In back off algorithm, whenever someone wins then in the next collision that person will again wins decreases.

The number of incorrect statement is ______________?