UGC NET CS 2016 Aug – II

Question 31

Which of the following protocols is used by email server to maintain a central repository that can be accessed from any machine ?

• POP3
• IMAP
• SMTP
• DMSP

Question 32

The number of strings of length 4 that are generated by the regular expression (0⁺1⁺|2⁺3⁺)*, where | is an alternation character and {+, *} are quantification characters, is:

• 08
• 09
• 10
• 12

Question 33

The content of the accumulator after the execution of the following 8085 assembly language program, is MVI A, 35H MOV B, A STC CMC RAR XRA B

• 00H
• 35H
• EFH
• 2FH

Question 34

In compiler optimization, operator strength reduction uses mathematical identities to replace slow math operations with faster operations. Which of the following code replacements is an illustration of operator strength reduction ?

• Replace P + P by 2 * P or Replace 3 + 4 by 7.
• Replace P * 32 by P < < 5
  
• Replace P * 0 by 0
• Replace (P < <4) – P by P * 15

Question 35

Which of the following are the principles tasks of the linker? I. Resolve external references among separately compiled program units. II. Translate assembly language to machine code. III. Relocate code and data relative to the beginning of the program. IV. Enforce access-control restrictions on system libraries.

• I and II
• I and III
• II and III
• I and IV

Question 36

Which of the following is FALSE?

• The grammar S→aS|aSbS|∈, where S is the only non-terminal symbol, and ∈ is the null string, is ambiguous.
• An unambiguous grammar has same left most and right most derivation.
• An ambiguous grammar can never be LR(k) for any k.
• Recursive descent parser is a top-down parser.

Question 37

Consider a system with seven processes A through G and six resources R through W. Resource ownership is as follows : process A holds R and wants T process B holds nothing but wants T process C holds nothing but wants S process D holds U and wants S & T process E holds T and wants V process F holds W and wants S process G holds V and wants U Is the system deadlocked ? If yes, ______ processes are deadlocked.

• No
• Yes, A, B, C
• Yes, D, E, G
• Yes, A, B, F

Question 38

Suppose that the virtual Address space has eight pages and physical memory with four page frames. If LRU page replacement algorithm is used, _____ number of page faults occur with the reference string. 0 2 1 3 5 4 6 3 7 4 7 3 3 5 5 3 1 1 1 7 2 3 4 1

• 13
• 12
• 11
• 10

Question 39

Consider a system having ‘m’ resources of the same type. These resources are shared by three processes P₁, P₂and P₃ which have peak demands of 2, 5 and 7 resources respectively. For what value of ‘m’ deadlock will not occur ?

• 70
• 14
• 13
• 7

Question 40

Five jobs A, B, C, D and E are waiting in Ready Queue. Their expected runtimes are 9, 6, 3, 5 and x respectively. All jobs entered in Ready queue at time zero. They must run in _____ order to minimize average response time if 3 < x < 5.

• B, A, D, E, C
• C, E, D, B, A
• E, D, C, B, A
• C, B, A, E, D