# Hackwithinfy

## TOC |Gate-2006| Previous Year Questions| Set-15

TOC |Gate-2006| Theory of Computation ( Automata) For S ∈ (0 + 1) * let d(s) denote the decimal value of s (e.g. d(101) = 5). Let L = {s ∈ (0 + 1)* d(s)mod5 = 2 and d(s)mod7 != 4}. Which one of the following statements is true?  [GATE – 2006] a. L is …

## TOC |Gate-2007| Previous Year Questions| Set-14

TOC |Gate-2007| Theory of Computation ( Automata) Which of the following problems is undecidable?  [GATE – 2007] a. Membership problem for CFGs.b. Ambiguity problem for CFGs.c. Finiteness problem for FSAs.d. Equivalence problem for FSAs. Answer : b) Which of the following is TRUE?  [GATE – 2007] a. Every subset of a regular set is regular.b. …

## TOC |Gate-2008| Previous Year Questions| Set-13

TOC |Gate-2008| Theory of Computation ( Automata) Which of the following is true for the language {ap|p is a prime} ?  [GATE – 2008] a. It is not accepted by a Turing Machineb. It is regular but not context-freec. It is context-free but not regulard. It is neither regular nor context-free, but accepted by a Turing machine Answer …

## TOC |Gate-2009| Previous Year Questions| Set-12

TOC |Gate-2009| Theory of Computation ( Automata) S → aSa|bSb|a|b; The language generated by the above grammar over the alphabet {a,b} is the set of : [GATE – 2009] a. All palindromes.b. All odd length palindromes.c. Strings that begin and end with the same symbol.d. All even length palindromes. Answer : b) Which one of …

## TOC |Gate-2010| Previous Year Questions| Set-11

TOC |Gate-2010| Theory of Computation ( Automata) Let L1 be a recursive language. Let L2 and L3 be languages that are recursively enumerable but not recursive. Which of the following statements is not necessarily true? [GATE – 2010] a. L2 – L1 is recursively enumerableb. L1 – L3 is recursively enumerablec. L2 ∩ L1 is …

## Operating System |Gate-2006| previous year question|Set-15

Operating System |Gate-2006| Consider three CPU-intensive processes, which require 10, 20 and 30 time units and arrive at times 0, 2 and 6, respectively. How many context switches are needed if the operating system implements a shortest remaining time first scheduling algorithm? Do not count the context switches at time zero and at the end. …

## Operating System |Gate-2007| previous year question|Set-14

Operating System |Gate-2007| 1. Group 1 contains some CPU scheduling algorithms and Group 2 contains some applications. Match entries in Group 1 to entries in Group 2. [GATE – 2007] a. P – 3 Q – 2 R – 1b. P – 1 Q – 2 R – 3c. P – 2 Q – 3 …

## Operating System |Gate-2008| previous year question|Set-13

Operating System |Gate-2008| The data blocks of a very large file in the Unix file system are allocated using  : [GATE – 2008]  a. contiguous allocationb. linked allocationc. indexed allocationd. an extension of indexed allocation Answer : d) Which of the following statements about synchronous and asynchronous I/O is NOT true? [GATE – 2008] a. …

## Operating System |Gate-2009| previous year question|Set-12

Operating System |Gate-2009| In which one of the following page replacement policies, Belady’s anomaly may occur? [GATE – 2009] a. FIFOb. Optimalc. MRUd. LRU Answer : a) The essential content(s) in each entry of a page table is / are : [GATE – 2009] a. Virtual page numberb. Page frame numberc. Both virtual page number …

## Operating System |Gate-2010| previous year question|Set-11

Operating System |Gate-2010| 1. Which of the following statements are true? [GATE – 2010] a. I onlyb. I and III onlyc. II and III onlyd. I, II and III Answer : d) 2. Consider the methods used by processes P1 and P2 for accessing their critical sections whenever needed, as given below. The initial values …