U.G.C. NET Exam. Dec. 2021-June 2022 Paper II (COMPUTER SCIENCE & APPLICATIONS).

Total Questions: 100

21. Consider a memory system having address spaced at a distance of m. T = Bank cycle time and n number of banks, then the average data access time per word access in synchromous organization is.

Correct Answer: (a)

Solution:

Given that

22. Answer the following question

(a) aaaa* (λ + b + bb + bbb)
(b) aaaaa* (b + bb + bbb)
(c) aaaaa* (λ + b + bb + bbb)
(d) aaaa* (b + bb + bbb)

Correct Answer: (c) aaaaa* (λ + b + bb + bbb)

Solution:

Given that

23. Answer the following question

Correct Answer: (a)

Solution:

24. Given below are two statements:

(a) Both statement I and Statement II are correct
(b) Both statement I and Statement II are incorrect
(c) Statement I is correct but statement II is incorrect
(d) Statement I is incorrect but statement

Correct Answer: (a) Both statement I and Statement II are correct

Solution:

Given statement I.

Condition field has four status bits, it needs 4 bits for
four different conditions branch field have four option
so, it needs 2 bits for four option.
So there 7 bit are required for 128 different location.
But BR field is used in conjuction with the address field
therefore the size of the address field is 7-2 = 5.
Intruction field is 20 bits.
So Statement I and Statement II is true.

25. Which mode as a block cipher implementation as a self synchronizing stream cipher?

(a) Cipher Block Chaining Mode
(b) Cipher Feedback Mode
(c) Electronic Codebook Mode
(d) Output Feedback Mode

Correct Answer: (b) Cipher Feedback Mode

Solution:

Cipher Block Chaining Mode (CBC) is a mode of operation for a block Chiper one in which a sequence of bits are encrypted as a single unit, or block, with a Chipher key applied to the entire block. Cipher block chaining uses what is know as an initialization vector (IV) of a certain length.
Cipher Feedback Mode
In this mode the Cipher is given as feedback to the next block of encryption with some new specifications. First, an Initial Vector (IV) is used for first encryption and output bits are divided as a set of 5 and b-s bits. The left hand side 5 bits are selected along with plaintext bit to which an XOR operation is applied. The result is given as input to a shift register having b-s bits to rhs, s bits to rhs and the process continues. The encryption and decryption process for the same is show below, both of them encryption algorithms.
Electronic code book mode–Electronic code book is the easiest block Cipher mode of functioning. It is easier because of direct encryption of each block of input plaintext and output is in form of blocks of encrypted Ciphertext. Generally, if a massage is larger than b bits in size, it can be broken down into a branch of block and the procedure is repeated. Output Feedback Mode–The output feedback it involves feeding the successive output block form the underlying block Cipher back to it. So option (b) is correct.

26. Consider the following:

(a)
(b)
(c)
(d)
(e) *

Correct Answer: (e) *

Solution:

Activation record – Subroutine call
Location counter – Assembler
Reference count – Garbage collection
Address relocation – Linking loader

27. Alpha and Beta testing are forms of

(a) White-Box Testing
(b) Black-Box Testing
(c) Acceptance Testing
(d) System Testing

Correct Answer: (c) Acceptance Testing

Solution:

Alpha and Beta testing are forms of acceptance testing and they both try to determine how an application and its features behave.
• When the goal is to obtain Alpha and Beta tests are typically run. That way, every application of the product can be tested and gather feedback internally and externally.
• Both of the ensure a good quality product.

28. Consider the properties of recursively enumerable sets :

(A) Finiteness (B) Context Freedom
(C) Emptiness
Which of the following is true?

(a) Only (A) and (B) are not decidable
(b) Only (B) and (c) are not decidable
(c) Only (C) and (A) are not decidable
(d) All (A), (B) and (C) are not decidable

Correct Answer: (d) All (A), (B) and (C) are not decidable

Solution:

Rice's theorem every non-trivial property ψ of the recursively enumerable languages in indecidable. Consequences of Rice's theorem.
The following properties of recursively enumerable set are not decidable.
(i) Emptiness (ii) Finiteness
(iii) Regnlerity (iv) Context Freedom
So option (d) is correct.

29. Which of the following is correct for the destination address 4A : 30 : 10 : 21 : 10 : 1A?

(a) unicast addres
(b) multicast addres
(c) broadcast addres
(d) unicast and broadcast address

Correct Answer: (a) unicast addres

Solution:

The destination address
4A:30:10:21:10:1A is
Unicast address.
A unicast address uniquely identifies a single interface by its address. An interface can have multiple unicast address and must have at least one link- local address. A link-local address is an address used on a link between two nodes.

30. The model in which the requirements are implemented by its category is

(a) Evolutionary Development Model
(b) Waterfall Model
(c) Prototyping Model
(d) Iterative Enhancement Model

Correct Answer: (c) Prototyping Model

Solution:

Evolutionary process model resembles the interative model. The same phases are defined for the waterfall model differs from the interative enhancement model in the sense that this does not require a useful product at the end of each cycle. In evolutionary development requirements are implemented by a category rather than by priority.