# Recent questions tagged nptel-quiz

1 vote
1
Consider a relation R(a,b,c) ordered on a non-key attribute b, and an index is maintained on attribute c. To evaluate the following expression, which is a better order of operation? σ(b= abc′∧c=12)(R) 1.First filter tuples u sing index on c and then search ... First search tuples for the given value of b and then use index on c 3.The order of operation does not matter 4.Insufficient data to answer
2
Consider two relations R and S of size 600 and 500 bytes respectively.The size of a tuple in both relations is 20B. The block size of the system is 200B. How would many extra block transfers be required, in the worst case, if nested loop join is used instead of block nested loop join technique to compute R⋈S? 1. 78 2. 93 3. 66 4. 105
3
Which of the following relational operators is commutative? 1. Difference, Union 2. Full outer join and Left outer join 3. Full outer join and intersection 4. Right outer join and Union
4
In what kind of index does an index entry appear only for certain keys? 1. Dense 2. Sparse 3. Simple 4. Inner
5
Consider the simple nested-loop join of the following two relations r and s. Relation r s Tuples (n) 2400 1500 Blocks (b) 40 50 Assuming the worst case memory availability, i.e., the memory can hold only one block of each relation at a time, what is the number of block ... 120040, seeks = 4800 2. Transfers = 4800, seeks = 120040 3. Transfers = 60050, seeks = 3000 4. Transfers = 3000, seeks = 60050
1 vote
6
In an external merge sort, where the number of blocks in the relation is 324, suppose we can put only 4 blocks at a time into the memory. In the worst case, how many totals seeks will happen? 1. ∼2400 2. ∼2700 3. ∼3000 4. ∼3300
7
In an external merge sort, where number of blocks in the relation is 324, suppose we can put only 4 blocks at a time into the memory. In the worst case, how many total block transfers will happen? 1. 2592 2. 3240 3. 3888 4. 4230
8
Which of the following does not interrupt a running process? 1. A device 2. Timer 3. Power Failure 4. None of the above
9
Let L be a language. We define another language L′ as follow L′={w∣w is binary equivalent of 2^x, where x∈L and consider x as a binary number} Which of the following is false? 1) If L is regular then L′ is also regular 2) If L is regular then L′ may not regular 3) L′ is always regular irrespective of L 4) L′ is always non-regular irrespective of L
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1. What is the difference between message integrity and message authentication ? I have read in frozen : message integrity -: message digest (generated by applying hash function on message ) is being added with original message and by verification of this digest(creating the ... are verifying digest in both for assurance of not modified data. Explain it pls. I m not able to visualise it . Thanks
11
Suppose we have a graph with negative edge weights. We take the largest magnitude negative edge weight -k and reset each edge weight w to w+k+1. Which of the following is true? 1. Kruskal's algorithm will identify the same spanning tree on the new graph as ... modified graph. 4. There are more minimum cost spanning trees in the modified graph than in the original graph. is the correct answer 3 ?
12
Voting in Siruseri Zonal Computing Olympiad 2010 Elections are on for the Siruseri Town Council. Elections in Siruseri work in a rather odd manner. Each candidate is assigned a unique identification number. The town is divided into five zones and each zone proposes a list of candidates, in some arbitrary ... 162 5 14 162 92 387 7 748 14 5 12 387 17 952 12 92 398 849 14 5 92 12 387 Sample Output 5
13
Suppose we want to sort an array in ascending order and we implement quicksort so that we always choose the last element in the array as the pivot element. Assume that the input is a permutation of {1, 2, , n}. Which of the following would definitely be a worst case ... some random order. {1, 2, . . . , n} with all odd numbers in ascending order followed by all even numbers in random order.
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Q6. ___________Data Encryption Standard (DES) was designed to increase the size of the Data Encryption Standard (DES) key. (A) Double (B) Triple (C) Quadruple (D) none of these
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Q3: What kind of ciphers Electronic Codebook (ECB) mode and Cipher Block Chaining (CBC) mode are (A) Block cipher (B) Stream cipher (C) Field cipher (D) both (A) and (B)
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State True or False . Please explain in 2 or 3 sentences Temporal locality states if a page is accessed, then there is a high chance that the nearby pages will be accessed.
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State true or false. When a user encounters a page fault, 1) The user application informs the OS, 2) User uses API calls to the hardware Memory Management unit, 3) Memory Management unit brings the page from hard disk to main memory. Is Statement 2 correct ?
18
In the Contiguous allocation for disk blocks, files cannot grow dynamically because _______ The next block could be occupied by another file The scheme does not allow files to grow (by design itself) (No answer is correct because files can grow) The disk does not have enough space I think both 1 and 2 are correct . What do you say ?
19
Creating many threads is advisable than creating many processes. Which of the statements below do not support this claim? Threads can share the address space and global data. None of the options. Programmer should ensure that it is ok to share data between two threads. Context switching is faster for threads as compared to Processes
20
State true or false. With Reason In a Micro-Kernel based OS, different modules communicate with each other using message passing. This is a secure way to enable communication. In a Modular OS, kernel modules can directly call any other module. This, however, ... enable communication. In a Modular OS, kernel modules can directly call any other module. This, however, suffers from efficiency issues.
21
Which of the following statements about Softwares is false? System Softwares provide an API that can be accessed by the Application Softwares. DBMS, Compilers, Assemblers are examples of System Software. OS Interface is used by the System Softwares to interact with the hardware/OS. System Softwares can control and coordinate the use of hardware.