Questions
1
The set A={ 0n 1n 2n | n=1, 2, 3, ......... } is an example of a grammar that is :
Answer: Option [A]
2
A slotted ALOHA network transmits 200-bit frames using a shared channel with a 200 Kbps bandwidth. Find the throughput of the system, if the system (all stations put together) produces 250 frames per second :
Answer: Option [B]
3
The period of a signal is 100 ms. Its frequency is _________.
Answer: Option [D]
4
The dotted-decimal notation of the following IPV4 address in binary notation is _________. 10000001 00001011 00001011 11101111
Answer: Option [A]
5
In Challenge-Response authentication the claimant ________.
Answer: Option [B]
6
Decrypt the message “WTAAD” using the Caesar Cipher with key=15.
Answer: Option [B]
7
To guarantee correction of upto t errors, the minimum Hamming distance dmin in a block code must be ________.
Answer: Option [B]
8
Encrypt the Message “HELLO MY DEARZ” using Transposition Cipher with
P lain Text 2 4 1 3
Key
Cipher Text 1 2 3 4
Answer: Option [B]
9
At a particular time of computation, the value of a counting semaphore is 10. Then 12 P operations and “x” V operations were performed on this semaphore. If the final value of semaphore is 7, x will be :
Answer: Option [B]
10
In a paged memory, the page hit ratio is 0.40. The time required to access a page in secondary memory is equal to 120 ns. The time required to access a page in primary memory is 15 ns. The average time required to access a page is ________.
Answer: Option [B]
11
In a multi-user operating system, 30 requests are made to use a particular resource per hour, on an average. The probability that no requests are made in 40 minutes, when arrival pattern is a poisson distribution, is _________.
Answer: Option [A]
12
Normally user programs are prevented from handling I/O directly by I/O instructions in them. For CPUs having explicit I/O instructions, such I/O protection is ensured by having the I/O instructions privileged. In a CPU with memory mapped I/O, there is no explicit I/O instruction. Which one of the following is true for a CPU with memory mapped I/O ?
Answer: Option [B]
13
Which UNIX/Linux command is used to make all files and sub-directories in the directory “progs” executable by all users ?
Answer: Option [D]
14
Page information in memory is also called as Page Table. The essential contents in each entry of a page table is/are _________.
Answer: Option [A]
15
Consider a virtual page reference string 1, 2, 3, 2, 4, 2, 5, 2, 3, 4. Suppose LRU page replacement algorithm is implemented with 3 page frames in main memory. Then the number of page faults are_________.
Answer: Option [B]
16
In which of the following scheduling criteria, context switching will never take place ?
Answer: Option [B]
17
In RDBMS, which type of Join returns all rows that satisfy the join condition ?
Answer: Option [B]
18
In a Hierachical database, a hashing function is used to locate the ________.
Answer: Option [B]
19
Relations produced from E - R Model will always be in ________.
Answer: Option [B]
20
A many-to-one relationship exists between entity sets r1 and r2. How will it be represented using functional depedencies if Pk(r) denotes the primary key attribute of relation r ?
Answer: Option [B]
