25 Questions
| Total Attempts: 54

Questions and Answers

- 1.A thread is usually defined as a ‘light weight process’ because an operating system (OS) maintains smaller data structures for a thread than for a process. In relation to this, which of the followings is TRUE?
- A.
On per-thread basis, the OS maintains only CPU register state

- B.
The OS does not maintain a separate stack for each thread

- C.
On per-thread basis, the OS does not maintain virtual memory state

- D.
On per thread basis, the OS maintains only scheduling and accounting information

- 2.The lexical analysis for a modern computer language such as Java needs the power of which one of the following machine models in a necessary and sufficient sense?
- A.
Finite state automata

- B.
Deterministic pushdown automata

- C.
Non-Deterministic pushdown automata

- D.
Turing machine

- 3.Let the page fault service time be 10ms in a computer with average memory access time being 20ns. If one page fault is generated for every 106 memory accesses, what is the effective access time for the memory? (A) 21ns (B) 30ns (C) 23ns (D) 35ns
- A.
21ns

- B.
30ns

- C.
23ns

- D.
35ns

- 4.Consider a hypothetical processor with an instruction of type LW R1, 20(R2), which during execution reads a 32-bit word from memory and stores it in a 32-bit register R1. The effective address of the memory location is obtained by the addition of constant 20 and the contents of register R2. Which of the following best reflects the addressing mode implemented by this instruction for the operand in memory?
- A.
Immediate addressing

- B.
Register Addressing

- C.
Register Indirect Scaled Addressing

- D.
Base Indexed Addressing

- 5.If two fair coins are flipped and at least one of the outcomes is known to be a head, what is the probability that both outcomes are heads?
- A.
1/3

- B.
1/4

- C.
1/2

- D.
2/3

- 6.Consider different activities related to email. m1: Send an email from a mail client to a mail server m2: Download an email from mailbox server to a mail client m3: Checking email in a web browser Which is the application level protocol used in each activity?
- A.
m1:HTTP m2:SMTP m3:POP

- B.
M1:SMTP m2:FTP m3:HTTP

- C.
M1: SMTP m2: POP m3: HTTP

- D.
M1: POP m2: SMTP m3:IMAP

- 7.Which of the following is NOT desired in a good Software Requirement Specifications (SRS) document?
- A.
Functional Requirements

- B.
Non Functional Requirements

- C.
Goals of Implementation

- D.
Algorithms for Software Implementation

- 8.Consider a relational table with a single record for each registered student with the following attributes. 1. Registration_Number: Unique registration number for each registered student 2. UID: Unique Identity number, unique at the national level for each citizen 3. BankAccount_Number: Unique account number at the bank. A student can have multiple accounts or joint accounts. This attributes stores the primary account number 4. Name: Name of the Student 5. Hostel_Room: Room number of the hostel Which of the following options is INCORRECT?
- A.
BankAccount_Number is a candidate key

- B.
Registration_Number can be a primary key

- C.
UID is a candidate key if all students are from the same country

- D.
If S is a superkey such that S UID ∩ is NULL then S ∪ UID is also a superkey

- 9.. Database table by name Loan_Records is given below. Borrower Bank_Manager Loan_ Amount Ramesh Sunderajan 10000.00 Suresh Ramgopal 5000.00 Mahesh Sunderajan 7000.00 What is the output of the following SQL query? SELECT count(*) FROM( (SELECT Borrower. Bank_Manager FROM Loan_Records) AS S NATURAL JOIN (SELECT Bank_Manager, Loan_Amount FROM Loan_Records) AS T );
- A.
3

- B.
9

- C.
5

- D.
6

- 10.On a non-pipelined sequential processor, a program segment, which is a part of the interrupt service routine, is given to transfer 500 bytes from an I/O device to memory. Initialize the address register Initialize the count to 500 LOOP: Load a byte from device Store in memory at address given by address register Increment the address register Decrement the count If count != 0 go to LOOP Assume that each statement in this program is equivalent to a machine instruction which takes one clock cycle to execute if it is a non-load/store instruction. The load-store instructions take two clock cycles to execute. The designer of the system also has an alternate approach of using the DMA controller to implement the same transfer. The DMA controller requires 20 clock cycles for initialization and other overheads. Each DMA transfer cycle takes two clock cycles to transfer one byte of data from the device to the memory. What is the approximate speedup when the DMA controller based design is used in place of the interrupt driven program based input-output?
- A.
3.4

- B.
4.4

- C.
3.6

- D.
5.1

- 11.Consider a database table T containing two columns X and Y each of type integer. After the creation of the table, one record (X= 1, Y=l) is inserted in the table. Let MX and MY denote the respective maximum values of X and Y among all records in the table at any point in time. Using MX and MY, new records are inserted in the table 128 times with X and Y values being MX+1, 2*MY+1 respectively. It may be noted that each time after the insertion, values of MX and MY change. What will be the output of the following SQL query after the steps mentioned above are carried out? SELECT Y FROM T WHERE X=7;
- A.
127

- B.
255

- C.
129

- D.
257

- 12.A deck of 5 cards (each carrying a distinct number from 1 to 5) is shuffled thoroughly. Two cards are then removed one at a time from the deck. What is the probability that the two cards are selected with the number on the first card being one higher than the number on the second card? (A) 1/5 (B) 4/25 (C) 1/4 (D) 2/5
- A.
1/5

- B.
3/25

- C.
1/4

- D.
2/5

- 13.. Consider the following table of arrival time and burst time for three processes P0, P1 and P2. Process Arrival time Burst Time P0 0 ms 9 ms P1 1 ms 4ms P2 2 ms 9ms The pre-emptive shortest job first scheduling algorithm is used. Scheduling is carried out only at arrival or completion of processes. What is the average waiting time for the three processes?
- A.
5.0ms

- B.
4.33ms

- C.
6.33ms

- D.
7.33ms

- 14.An index is clustered, if
- A.
It is on a set of fields that form a candidate key.

- B.
It is on a set of fields that include the primary key.

- C.
The data records of the file are organized in the same order as the data entries of the index.

- D.
The data records of the file are organized not in the same order as the data entries of the index.

- 15.The transport layer protocols used for real time multimedia, file transfer, DNS and email, respectively are
- A.
TCP, UDP, UDP and TCP

- B.
UDP, TCP, TCP and UDP

- C.
UDP, TCP, UDP and TCP

- D.
TCP, UDP, TCP and UDP

- 16.A scheduling algorithm assigns priority proportional to the waiting time of a process. Every process starts with priority zero(the lowest priority). The scheduler re-evaluates the process priorities every T time units and decides the next process to schedule. Which one of the following is TRUE if the processes have no I/O operations and all arrive at time zero?
- A.
This algorithm is equivalent to the first-come-first-serve algorithm.

- B.
This algorithm is equivalent to the round-robin algorithm.

- C.
This algorithm is equivalent to the shortest-job-first algorithm.

- D.
This algorithm is equivalent to the shortest-remaining-time-first algorithm.

- 17.Suppose p is number of cars per minute passing through a certain road junction between 5 PM and 6PM, and p has a Poisson distribution with mean 3. What is the probability of observing fewer than 3 cars during any given minute in this interval?
- A.
( 3 ) 8 / 2e

- B.
( 3 ) 9 / 2e

- C.
17 / 2e

- D.
26 / 2e

- 18.In an IPv4 datagram, the M bit is 0, the value of HLEN is 10, the value of total length is 400 and the fragment offset value is 300. The position of the datagram, the sequence numbers of the first and the last bytes of the payload, respectively are
- A.
Last fragment, 2400 and 2789

- B.
First fragment, 2400 and 2759

- C.
Last fragment, 2400 and 2759

- D.
Middle fragment, 300 and 689

- 19.Determine the maximum length of cable (in km) for transmitting data at a rate of 500 Mbps in an Ethernet LAN with frames of size 10,000 bits. Assume the signal speed in the cable to be 2,00,000 km/s
- A.
1

- B.
2

- C.
2.5

- D.
5

- 20.A shared variable x, initialized to zero, is operated on by four concurrent processes W, X, Y, Z as follows. Each of the processes W and X reads x from memory, increments by one, stores it to memory, and then terminates. Each of the processes Y and Z reads x from memory, decrements by two, stores it to memory, and then terminates. Each process before reading x invokes the P operation (i.e., wait) on a counting semaphore S and invokes the V operation (i.e., signal) on the semaphore S after storing x to memory. Semaphore S is initialized to two. What is the maximum possible value of x after all processes complete execution?
- A.
-2

- B.
-1

- C.
1

- D.
2

- 21.Which of the following statements is/are TRUE for undirected graphs? P: Number of odd degree vertices is even. Q: Sum of degrees of all vertices is even.
- A.
P only

- B.
Q only

- C.
Both P and Q

- D.
Neither P nor Q

- 22.Function f is known at the following points: X 0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 f(x) 0 0.09 0.36 0.81 1.44 2.25 3.24 4.41 5.76 7.29 9.00 The value of integral 0-3 f(x)dx computed using the trapezoidal rule is
- A.
8.983

- B.
9.003

- C.
9.017

- D.
9.045

- 23.Which of the following statements are TRUE? (1) The problem of determining whether there exists a cycle in an undirected graph is in P. (2) The problem of determining whether there exists a cycle in an undirected graph is in NP. (3) If a problem A is NP-Complete, there exists a non-deterministic polynomial time algorithm to solve A.
- A.
1,2 and 3

- B.
1 and 2

- C.
1 and 3

- D.
2 and 3

- 24.Which one of the following is the tightest upper bound that represents the time complexity of inserting an object into a binary search tree of n nodes?
- A.
O(1)

- B.
O(log n)

- C.
O(n)

- D.
O(n log n)

- 25.Which one of the following is the tightest upper bound that represents the time complexity of inserting an object into a binary search tree of n nodes?
- A.
O(1)

- B.
O l(og n)

- C.
O(n)

- D.
O(n logn)