December 2015 - Paper 2

46:  

A unix file system has 1-KB blocks and 4-byte disk addresses. What is the maximum file size if i-nodes contain 10 direct entries and one single, double and triple indirect entry each?

A.

32 GB

B.

64 GB

C.

16 GB

D.

1 GB

 
 

Option: C

Explanation :

block = 2 10
 
block pointer size = 4B
 
entries possible in block = 2 10 /2 2  = 256
 
direct pointer gives = 10 * 256 = 10 blocks
 
single indirect gives = 256 * 256 = 2 8  blocks
 
double indirect gives = 256 * 256 * 256 = 2 16  blocks
 
triple indirect gives = 256 * 256 * 256 * 256 = 2 24  blocks
 
total = 10 blocks + 2 8  blocks + 2 16  blocks + 2 24  blocks
 
= 16843018 blocks = 16843018 * 1024 = 17247250432 ≈ 16 GB

Click on Discuss to view users comments.

Write your comments here:



47:  

 ................. uses electronic means to transfer funds directly from one account to another rather than by cheque or cash?

A.

M-Banking

B.

E-Banking

C.

O-Banking

D.

C-Banking

 
 

Option: B

Explanation :

Click on Discuss to view users comments.

Write your comments here:



48:  

Which of the following arguments are not valid?

(a) “If Gora gets the job and works hard, then he will be promoted. If Gora gets promotion, then he will be happy. He will not be happy, therefore, either he will not get the job or he will not work hard”.

(b) “Either Puneet is not guilty or Pankaj is telling the truth. Pankaj is not telling the truth, therefore, Puneet is not guilty”.

(c) If n is a real number such that n>1, then n2>1. Suppose that n2>1, then n>1.

A.

(a) and (c)

B.

(b) and (c)

C.

(a), (b) and (c)

D.

(a) and (b)

 
 

Option: A

Explanation :

(a) P: Gora gets the job

    Q: Gora works hard

    R: Gora gets promotion

    S: Gora will be happy

The argument can bet written as

   (P˄Q)→R

R→S

 ¬S

Therefore       ¬P˅¬Q

                           

(b)  Let       P: Puneet is not guilty

                  Q: Pankaj is telling the truth

The argument can bet written as

P˅Q

~Q

Therefore,      P

Thus by disjunctive syllogism, the argument is valid.

Disjunctive Syllogism:

The disjunctive syllogism rule may be written as:

P˅Q, ¬P ⊢Q

It may also be written as:

((P˅Q)˄¬P)→Q

where P, and Q are propositions expressed in some formal system.

Click on Discuss to view users comments.

Write your comments here:



49:  

A virtual memory has a page size of 1K words. There are eight pages and four blocks. The associative memory page table contains the following entries:

Which of the following list of virtual addresses (in decimal) will not cause any page fault if referenced by the CPU?

Page Block
0 3
2 1
5 2
7 0

 

A.

1024, 3072, 4096, 6144

B.

1234, 4012, 5000, 6200

C.

1020, 3012, 6120, 8100

D.

2021, 4050, 5112, 7100

 
 

Option: C

Explanation :

The pages which are not in main memory are:

Page

Address

Address that will cause page fault

1

1K

1024-2047

3

3K

3072-4095

4

4K

4096-5119

6

6K

6144-7167

1020 will not cause page fault (1024-2047)

3012 will not cause page fault (3072-4095)

6120 will not cause page fault (4096-5119)

8100 will not cause page fault (6144-7167)

Click on Discuss to view users comments.

Write your comments here:



50:  

A system has four processes and five allocatable resources. The current allocation and maximum needs are as follows:

 

Allocated

Maximum

Available

Process A

1 0 2 1 1

1 1 2 1 3

0 0 x 1 1

Process B

2 0 1 1 0

2 2 2 1 0

 

Process C

1 1 0 1 0

2 1 3 1 0

 

Process D

1 1 1 1 0

1 1 2 2 1

 

The smallest value of x for which the above system in safe state is .............

A.

1

B.

3

C.

2

D.

0

 
 

Option: D

Explanation :

If Process A’s Maximum need is 1 1 2 1 2 instead of 1 1 2 1 3, then answer will be x=1

The needs matrix is as follows:

0 1 0 0 1

0 2 1 0 0

1 0 3 0 0

0 0 1 1 1

If x is 0, available vector will be 0 0 0 1 1, we have a deadlock immediately.

If x is 1, available vector will be 0 0 1 1 1, now, process D can run to completion. When it is finished, the available vector is 1 1 2 2 1.

Now A can run to complete, the available vector then becomes 2 1 4 3 2.

Then C can run and finish, return the available vector as 3 2 4 4 2.

Then B can run to complete. Safe sequence D A C B.

Click on Discuss to view users comments.

Write your comments here:



Related MCQ