GATE-IT-2004

Question 71

Assume that the delivered lines of code L of a software is related to the effort E in person months and duration t in calendar months by the relation L P* (E/B)^1/3 * t^4/3, where P and B are two constants for the software process and skills factor. For a software project, the effort was estimated to be 20 person months and the duration was estimated to be 8 months. However, the customer asked the project team to complete the software project in 4 months. What would be the required effort in person months?  

• 10
• 40
• 160
• 320

Question 72

A disk has 200 tracks (numbered 0 through 199). At a given time, it was servicing the request of reading data from track 120, and at the previous request, service was for track 90. The pending requests (in order of their arrival) are for track numbers. 30 70 115 130 110 80 20 25. How many times will the head change its direction for the disk scheduling policies SSTF(Shortest Seek Time First) and FCFS (First Come Fist Serve)

• 2 and 3
• 3 and 3
• 3 and 4
• 4 and 4

Question 73

In a certain operating system, deadlock prevention is attempted using the following scheme. Each process is assigned a unique timestamp, and is restarted with the same timestamp if killed. Let Ph be the process holding a resource R, Pr be a process requesting for the same resource R, and T(Ph) and T(Pr) be their timestamps respectively. The decision to wait or preempt one of the processes is based on the following algorithm.

 if T(Pr) < T(Ph)

     then kill Pr

else wait

Which one of the following is TRUE?

• The scheme is deadlock-free, but not starvation-free
• The scheme is not deadlock-free, but starvation-free
• The scheme is neither deadlock-free nor starvation-free
• The scheme is both deadlock-free and starvation-free

Question 74

A process executes the following segment of code :

 for(i = 1; i < = n; i++)

fork (); 

The number of new processes created is  

• n
• ((n(n + 1))/2)
• 2ⁿ - 1
• 3ⁿ - 1

Question 75

The semaphore variables full, empty and mutex are initialized to 0, n and 1, respectively. Process P₁ repeatedly adds one item at a time to a buffer of size n, and process P₂ repeatedly removes one item at a time from the same buffer using the programs given below. In the programs, K, L, M and N are unspecified statements.

P1

while (1) {     K; P(mutex); Add an item to the buffer; V(mutex);     L; } P2 while (1) {    M; P(mutex); Remove an item from the buffer; V(mutex);     N; } The statements K, L, M and N are respectively

• P(full), V(empty), P(full), V(empty)
• P(full), V(empty), P(empty), V(full)
• P(empty), V(full), P(empty), V(full)
• P(empty), V(full), P(full), V(empty)

Question 76

In a virtual memory system, size of virtual address is 32-bit, size of physical address is 30-bit, page size is 4 Kbyte and size of each page table entry is 32-bit. The main memory is byte addressable. Which one of the following is the maximum number of bits that can be used for storing protection and other information in each page table entry?

• 2
• 10
• 12
• 14

Question 77

A software was tested using the error seeding strategy in which 20 errors were seeded in the code. When the code was tested using the complete test suite, 16 of the seeded errors were detected. The same test suite also detected 200 non-seeded errors. What is the estimated number of undetected errors in the code after this testing?

• 4
• 50
• 200
• 250

Question 78

What is the availability of a software with the following reliability figures? Mean Time Between Failure (MTBF) = 25 days Mean Time To Repair (MTTR) = 6 hours  

• 1%
• 24%
• 99%
• 99.009%

Question 79

Consider the following entity relationship diagram (ERD), where two entities E1 and E2 have a relation R of cardinality 1 : m.

The attributes of E1 are A11, A12 and A13 where A11 is the key attribute. The attributes of E2 are A21, A22 and A23 where A21 is the key attribute and A23 is a multi-valued attribute. Relation R does not have any attribute. A relational database containing minimum number of tables with each table satisfying the requirements of the third normal form (3NF) is designed from the above ERD. The number of tables in the database is

• 2
• 3
• 5
• 4

Question 80

A relational database contains two tables student and department in which student table has columns roll_no, name and dept_id and department table has columns dept_id and dept_name. The following insert statements were executed successfully to populate the empty tables:

Insert into department values (1, \'Mathematics\')
Insert into department values (2, \'Physics\')
Insert into student values (l, \'Navin\', 1)
Insert into student values (2, \'Mukesh\', 2)
Insert into student values (3, \'Gita\', 1) 

How many rows and columns will be retrieved by the following SQL statement?

Select * from student, department

• 0 row and 4 columns
• 3 rows and 4 columns
• 3 rows and 5 columns
• 6 rows and 5 columns