UGC NET CS 2015 Jun - III

Question 51

In propositional logic P ↔ Q is equivalent to (Where ~ denotes NOT):

• ~( P ∨ Q ) ∧ ~ ( Q ∨ P )
• ( ~P ∨ Q ) ∧ (~ Q ∨ P )
• ( P ∨ Q ) ∧ ( Q ∨ P )
• ~( P ∨ Q ) → ~ ( Q ∨ P )

Question 52

Which of the following statements is true for Branch - and - Bound search?

• Underestimates of remaining distance may cause deviation from optimal path.
• Overestimates can\'t cause right path to be overlooked.
• Dynamic programming principle can be used to discard redundant partial paths.
• All of the above

Question 53

Match the following:

List - I	List - II
(a) Joint Application Design (JAD)	(i) Delivers functionality in rapid iteration measured in weeks and needs frequent communication, development, testing and delivery
(b) Computer Aided Software Engg	(ii) Reusable applications generally with one specific function. It is closely linked with idea of web services and service oriented architecture.
(c)Agile development	(iii)Tools to automate many tasks of SDLC
(d) Component based technology	(iv) A group based tool for collecting user requirements and creating system design. Mostly used in analysis and design stages of SDLC.

codes:

	(a)	(b)	(c)	(d)
(1)	(i)	(iii)	(ii)	(iv)
(2)	(iv)	(i)	(ii)	(iii)
(3)	(i)	(iv)	(ii)	(iii)
(4)	(iv)	(ii)	(i)	(iii)

• (1)
• (2)
• (3)
• (4)

Question 54

A context free grammar for L = { w | n₀ ( w ) > n₁ ( w ) } is given by:

• S → 0 | 0 S | 1 S S
• S → 0 S | 1 S | 0 S S | 1 S S | 0 | 1
• S → 0 | 0 S | 1 S S | S 1 S | S S 1
• S → 0 S |1 S | 0 | 1

Question 55

Given the following two statements: S₁:If L₁ and L₂ are recursively enumerable languages over ∑, then L₁ ∪ L ₂ and L₂ ∩ L₂ are also recursively enumerable. S₂: The set of recursively enumerable languages is countable. Which of the following is correct ?

• S ₁ is correct and S ₂ is not correct
• S ₁ is not correct and S ₂ is correct
• Both S ₁ and S ₁ are not correct.
• Both S ₁ and S ₁ are correct.

Question 56

Given the following grammars: 
G₁: S → AB|aaB 
A → aA | ∈ 
B → bB | ∈ 
G₂: S → A|B 
A → aAb | ab 
B → abB | ∈ 

Which of the following is correct?

• G ₁ is ambiguous and G ₂ is unambiguous grammars

• G ₁ is unambiguous and G ₂ is ambiguous grammars

• both G ₁ and G ₂ are ambiguous grammars

• both G ₁ and G ₂ are unambiguous grammars

Question 57

Given the symbols A, B, C, D, E, F, G and H with the probabilities 1 / 30, 1 / 30, 1 / 30, 2 / 30, 3 / 30, 5 / 30, 5 / 30, and 12 / 30 respectively. The average Huffman code size in bits per symbol is:

• 67 / 30

• 70 / 30

• 76 / 30

• 78/ 30

Question 58

The redundancy in images stems from:

• pixel decorrelation
• pixel correlation
• pixel quantization
• image size

Question 59

In a binary Hamming Code the number of check digits is r then number of message digits is equal to:

• 2^r - 1
• 2^r - r - 1
• 2^r - r + 1
• 2^r + r - 1

Question 60

In the Hungarian method for solving assignment problem, an optimal assignment requires that the maximum number of lines that can be drawn through squares with zero opportunity cost be equal to the number of:

• rows or columns
• rows + columns
• rows + columns - 1
• rows + columns + 1