## Introduction

UGC NET Exam is a very popular exam in India for people interested in the research domain. NET(National Eligibility Test) is conducted by NTA (NATIONAL TESTING AGENCY) to identify qualified candidates for Assistant Professor positions in colleges and universities, as well as Junior Research Fellowships (JRF). This article will discuss the UGC NET Exam of UGC NET solutions from questions 51 to 75. You can find the solutions to Q1 to 25 __Aug 2016 Paper-III (Re-Test) - Part 1__ and Q26 to 50 in UGC NET __Aug 2016 Paper-III (Re-Test) - Part 2__.

## Questions

**51. An operating system supports a paged virtual memory, using a central processor with a cycle time of one microsecond. It costs an additional one microsecond to access a page other than the current one. Pages have 1000 words, and the paging device is a drum that rotates at 3000 revolutions per minute and transfers one million words per second. Further, one percent of all instructions executed accessed a page other than the current page. The instruction that accessed another page, 80% accessed a page already in memory and when a new page was required, the replaced page was modified 50% of the time. What is the effective access time on this system, assuming that the system is running only one process and the processor is idle during drum transfers ?**

**(A) 30 microseconds (B) 34 microseconds**

**(C) 60 microseconds (D) 68 microseconds**

**Answer: B**

**Solution:** Effective access time = 0.99 * (1 µs) + 0.8 *.02 µs + 0.001 * ( 10000 µs + 1000 µs) + 0.001 * (20000 µs + 2000 µs)

= (0.99 +0.016+22.0+11.0) µs

= 34 µs

**52. Consider the following page reference string :****1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3, 2, 1, 2, 3, 6****Which of the following options, gives the correct number of page faults related to LRU, FIFO, and optimal page replacement algorithms respectively, assuming 05 page frames and all frames are initially empty ?****(A) 10, 14, 8 (B) 8, 10, 7****(C) 7, 10, 8 (D) 7, 10, 7**

**Answer: B****Solution:** In LRU total page fault will be: 8

In FIFO total page fault will be: 10

In Optimal total page, fault will be: 7

**53.Consider a file currently consisting of 50 blocks. Assume that the file control block and the index block is already in memory. If a block is added at the end (and the block information to be added is stored in memory), then how many disk I/O operations are required for indexed (single-level) allocation strategy ?****(A) 1 (B) 101****(C) 27 (D) 0**

**Answer: A****Solution: **The file control block and the index block are already in memory, according to the inquiry. As a result, we won't need to move them to another location for subsequent operations. This is a single operation if a block is added at the end (and the block information to be added is saved in memory). As a result, the indexed (single-level) allocation approach only requires one I/O operation.

**54. An experimental file server is up 75% of the time and down for 25% of the time due to bugs. How many times does this file server have to be replicated to give an availability of at least 99% ?****(A) 2 (B) 4****(C) 8 (D) 16**

**Answer: B****Solution:**If we have four replications, that means down time is 25%, which equals 0.25.

According to 4 replications, we have to multiply by 0.25*0.25*0.25*0.25

= 0.00390625

Availability= 100-0.0390625%

= 99.9609375%

**55. Given the following two languages:****L1 = {uwwRn | u, v, w ϵ {a, b}+}****L2 = {uwwRn | u, v, w ϵ {a, b}+, |u| ≥ |v|}****Which of the following is correct ?****(A) L1 is regular language and L2 is not regular language.****(B) L1 is not regular language and L2 is regular language.****(C) Both L1 and L2 are regular languages.****(D) Both L1 and L2 are not regular languages.**

**Answer: A****Solution: **Since wwR is present, we should have either aa or bb at some point in the string for L1.

Language L1 has a regular expression of r1=(a+b)+(aa+bb)(a+b)+, whereas Language L2 has a comparison of the lengths of u and v that DFA cannot do.

**56. Given a Turing Machine****M = ({q0, q1}, {0, 1}, {0, 1, B}, δ, B, {q1})****Where δ is a transition function defined as****δ (q0, 0) = (q0, 0, R)****δ (q0, B) = (q1, B, R)****The language L(M) accepted by Turing machine is given as :****(A) 0* 1* (B) 00*****(C) 10* (D) 1*0*****Answer: B****Solution:**

**57. Let G = (V, T, S, P) be a context-free grammar such that every one of its productions is of the form A → n, with |v| = k > 1. The derivation tree for any string W ϵ L (G) has a height such that**

**Answer: D****Solution: **Any tree's minimum height is logk|W|, whereas its maximum height is log2|W|+1 (because k>1, consider k=2).

In general, logk((|w|-1) / (k-1)) should be used.

**58. Which of the following is not used in standard JPEG image compression?****(A) Huffman coding (B) Runlength encoding****(C) Zig-zag scan (D) K-L Transform****Answer: D****Solution:**A stochastic process is represented as an infinite linear combination of orthogonal functions in the K-L Transform, which is equivalent to a Fourier series representation of a function on a bounded interval. The transformation is also known as the Hotelling transform or the eigenvector transform, and it is closely related to the principal component analysis (PCA) technique, which is widely used in image processing and data analysis.

**59. Which of the following is a source coding technique?****(A) Huffman coding (B) Arithmetic coding****(C) Run-length coding (D) DPCM****Answer: D****Solution: **Differential pulse-code modulation (DPCM) is a signal encoder that builds on the foundation of pulse-code modulation (PCM) by adding functionality based on signal sample prediction. An analogue or digital signal can be used as the input.

**60.If the histogram of an image is clustered towards origin on X-axis of a histogram plot then it indicates that the image is .............****(A) Dark (B) Good contrast****(C) Bright (D) Very low contrast**

**Answer: A****Solution: **The majority of the data points in a histogram for a very dark image will be on the left side and center of the graph. An extremely bright image with few black areas and/or shadows, on the other hand, will have the majority of its data points on the right side and center of the graph.

** 61.Consider the following linear programming problem:****Max. z = 0.50x2 – 0.10x1****Subject to the constraints****2x1 + 5x2 ≤ 80****x1 + x2 ≤ 20****and x1, x2 ≥ 0****The total maximum profit (z) for the above problem is:****(A) 6 (B) 8****(C) 10 (D) 12**

**Answer: B****Solution:**

2x1 + 5x2 ≤ 80

x1/40 + x2/16 ≤ 1 —-------(1)

x1/20 + x2/20 ≤ 1 —--------(2)

Solving equation (1) & (2)

x1 = (20/3)

x2 = (40/3)

Putting the value of x1 and x2 in equation z = 0.50x2 – 0.10x1

at (0,0) → z=6

at [(20/3 ,(40/3)] → z= 8

at (0, 16) → z = -2

at (20 ,0) → z= 0

**62. Consider the following statements:****(a) If primal (dual) problem has a finite optimal solution, then its dual (primal) problem has a finite optimal solution.****(b) If primal (dual) problem has an unbounded optimum solution, then its dual (primal) has no feasible solution at all.****(c) Both primal and dual problems may be infeasible.****Which of the following is correct?****(A) (a) and (b) only (B) (a) and (c) only****(C) (b) and (c) only (D) (a), (b) and (c)**

**Answer: D****Solution: **All the above statements are correct.

**63. Consider the following statements :****(a) Assignment problem can be used to minimize the cost.****(b) Assignment problem is a special case of transportation problem.****(c) Assignment problem requires that only one activity be assigned to each resource.****Which of the following options is correct?****(A) (a) and (b) only (B) (a) and (c) only****(C) (b) and (c) only (D) (a), (b) and ©****Answer: D****Solution: **A specific example of the transportation problem is the assignment problem. It just needs that each resource is assigned to one task, and it can be utilized to save costs.

All of the statements are true.

**64. What are the following sequence of steps taken in designing a fuzzy logic machine ?****(A) Fuzzification → Rule evaluation → Defuzzification****(B) Fuzzification → Defuzzification → Rule evaluation****(C) Rule evaluation → Fuzzification → Defuzzification****(D) Rule evaluation → Defuzzification → Fuzzification****Answer: A**

Solution: The fuzzy reasoning method is implemented into a system known as a Fuzzy Inferencing System. There are three steps to it:

1 – Fuzzification

2 – Rule evaluation(inferencing)

3 – Defuzzification

**65. Which of the following 2 input Boolean logic functions is linearly inseparable?****(a) AND (b) OR****(c) NOR (d) XOR****(e) NOT XOR****(A) (a) and (b) (B) (b) and (c)****(C) (c), (d) and (e) (D) (d) and (e)**

**Answer: D****Solution: **Boolean function with 2 attributes:

01) a -> separable

02) b -> separable

03) not a -> separable

04) not b -> separable

05) a and b -> separable

06) a or b -> separable

07) a xor b -> not separable

08) a nand b -> separable

09) a nor b -> separable

10) a xnor b -> not separable

11) (not a) and b -> separable

12) a and (not b) -> separable

13) (not a) or b -> separable

14) a or (not b) -> separable

**66. Let R and S be two fuzzy relations defined as**

**Then, the resulting relation, T, which relates elements of universe of X to elements of universe of Z using max-product composition is given by**

**Answer: C**

**Solution: **

**67. Consider the following operations to be performed in Unix:****“The pipe sorts all files in the current directory modified in the month of “June” by order of size and prints them to the terminal screen. The sort option skips ten fields then sorts the lines in numeric order.”****Which of the following Unix command will perform above set of operations?****(A) ls – l | grep “June” | sort + 10n****(B) ls – l | grep “June” | sort + 10r****(C) ls – l | grep – v “June” | sort + 10n****(D) ls – l | grep – n “June” | sort + 10x**

**Answer: A**

**Solution:** ls- It displays all files in the current directory.

ls -l displays all information (like permissions,links,size,type of file,file name,date of modification)

grep command (global search for the regular expression) is a filter that searches for lines that match a defined pattern and prints them to standard output.

To sort in ascending or descending order, use sort. It sorts in ascending order by default. The –n option is used to sort a file numerically. The -n option, like the others, is preset in Unix. This option is used to sort a file that contains numeric data.

**68.Which of the following statements is incorrect for a Windows Multiple Document Interface (MDI)?****(A) Each document in an MDI application is displayed in a separate child window within the client area of the application’s main window.****(B) An MDI application has three kinds of windows namely a frame window, an MDI client window and number of child windows.****(C) An MDI application can support more than one kind of document.****(D) An MDI application displays output in the client area of the frame window.**

**Answer: D****Solution: **A multiple document interface (MDI) is a graphical user interface in which several windows are grouped under one parent window. Such systems frequently allow child windows to contain additional windows, resulting in complicated nested hierarchies. This is in contrast to single document interfaces (SDI), which have all windows independent of one another. And it displays output in the client area of the frame window.

**69.Which of the following statement(s) is/are True regarding ‘nice’ command of UNIX?****I. It is used to set or change the priority of a process.****II. A process’s nice value can be set at the time of creation.****III. ‘nice’ takes a command line as an argument.****(A) I, II only (B) II, III only****(C) I, II, III (D) I, III only**

**Answer: C****Solution: **Nice corresponds to the same-named kernel call. Nice is used to give a utility or shell script a higher or lower priority than other processes, giving it more or less CPU time. A niceness score of 20 indicates the highest priority, while a score of 19 indicates the lowest importance. Processes inherit their default niceness from their parent process, which is normally 0.

**70. Let v(x) mean x is a vegetarian, m(y) for y is meat, and e(x, y) for x eats y. Based on these, consider the following sentences:****I. ∀x v(x) ⇔ (∀y e(x, y) ⇒ ¬m(y))****II. ∀x v(x ) ⇔ (¬(∃y m(y) ˄ e(x, y)))****III. ∀x (∃y m(y) ˄ e(x, y)) ⇔ ¬v(x)****One can determine that****(A) Only I and II are equivalent sentences****(B) Only II and III are equivalent sentences.****(C) Only I and III are equivalent sentence.****(D) I, II, and III are equivalent sentences.**

**Answer: D****Solution: **I.) If x is vegetarian then all food items he eats must not a meat item

II) If x is vegetarian then there should not at least one mean item that x eats

III) If there exists one meat item that x eats then x is not a vegetarian

All these sentences are equivalent

**71.Match each Artificial Intelligence term in List-I that best describes a given situation in List – II:****List – I List – II****I. Semantic Network a. Knowledge about what to do as opposed to****how to do it.****II. Frame b. A premise of a rule that is not concluded****by any rule.****III. Declarative knowledge c. A method of knowledge representation that****uses a graph.****IV. Primitive d. A data structure representing stereotypical****knowledge.****Codes :**** I II III IV****(A) d a b c****(B) d c a b****(C) d c b a****(D) c d a b****Answer: D****Solution:** A semantic network is a graph-based approach of knowledge representation.

A data structure that represents stereotyped knowledge is called a frame.

Declarative knowledge refers to knowing what to do rather than how to do it.

A premise of a rule that is not concluded by any rule is called primitive.

**72.In Artificial Intelligence , a semantic network****(A) is a graph-based method of knowledge representation where nodes represent concepts and arcs represent relations between concepts.****(B) is a graph-based method of knowledge representation where nodes represent relations between concepts and arcs represent concepts.****(C) represents an entity as a set of slots and associated rules.****(D) is a subset of first-order logic.****Answer: A****Solution: **A semantic network is a graph-based approach of knowledge representation in Artificial Intelligence, where nodes represent concepts and arcs represent relationships between concepts. In other terms, a Semantic Network is a graph-based approach of knowledge representation.

**73. Criticism free idea generation is a factor of ..............****(A) Decision Support System****(B) Group Decision Support System****(C) Enterprise Resource Support System****(D) Artificial Intelligence****Answer: B****Solution: **A feature of the Group Decision Support System is a criticism-free idea generating.

**74.Consider the following logical inferences :****I1 : If it is Sunday then school will not open.****The school was open.****Inference : It was not Sunday.****I2 : If it is Sunday then school will not open.****It was not Sunday.****Inference : The school was open.****Which of the following is correct?****(A) Both I1 and I2 are correct inferences.****(B) I1 is correct but I2 is not a correct inference.****(C) I1 is not correct but I2 is a correct inference.****(D) Both I1 and I2 are not correct inferences.**

**Answer: B****Solution:** p: it is Sunday

q: the school will open

As a result, if it is a Sunday, the school will be closed.

p-->~q so it can imply q->~p (by contrapositive) so the first inference is correct for the second

If it's a Sunday, the school won't be open, which is shown by

p-->~q

Given p, it can't imply p—>q (inverse implementation) unless the converse(q->p) is true, which isn't the case here.

**75.Which formal system provides the semantic foundation for Prolog?****(A) Predicate calculus (B) Lambda calculus****(C) Hoare logic (D) Propositional logic****Answer: A****Solution:**Prolog's semantic base is provided by predicate calculus.