UGC NET Paper 2 Computer Science Mock Test - 4 - UGC NET MCQ

Answer --> a - iii, b - iv, c - i, d - ii

Explanation -

FTP (File Transfer Protocol) -> File Transfer
FTP is a protocol that is used for transferring files over a network. It is a standard protocol that is used for uploading and downloading files from a server to a client or vice versa.

TFTP (Trivial File Transfer Protocol) -> Trivial File Transfer
TFTP is a simplified version of FTP that is used for transferring small files over a network. It is a lightweight protocol that does not provide authentication or encryption.

Telnet -> Remote Login
Telnet is a protocol that is used for remote login to a server or a networking device. It enables a user to access and control a remote computer over a network connection.

UDP (User Datagram Protocol) -> Send Datagram
UDP is a protocol that is used for sending datagrams over a network. It is a connectionless protocol that does not provide any reliability or error checking. It is commonly used for applications that require the fast transmission of data, such as online gaming and video streaming.

Concept:

Using digital logic concept, we can find out whether Boolean expressions is a tautology or not.

• In digital logic, we can write OR as +, AND as . , Negation as complement.

     
Explanation:

Option 1:

Option 1 is tautology.

Option 3:

The correct answer is option 3.

Concept:

Statement 1: The Uniform Resource Identifier is a set of rules which is used to retrieve linked web pages across the web.

False, The HyperText Transfer Protocol is a set of rules which is used to retrieve linked web pages across the web. The more secure and advanced version is HTTPS.

HTTP is a protocol for fetching resources such as HTML documents. It is the foundation of any data exchange on the Web and it is a client-server protocol, which means requests are initiated by the recipient, usually the Web browser.

Statement 2: HyperText Transfer Protocol is a unique address or path for each resource located on the web.

False, URI (Uniform Resource Identifier) or URL (Uniform Resource Locator) is a unique address or path for each resource located on the web.

A Uniform Resource Identifier (URI) is a character sequence that identifies a logical (abstract) or physical resource usually, but not always, connected to the internet.

Hence the correct answer is Both statement 1 and statement 2.

A self-organizing map:

• It is a type of artificial neural network (ANN) that is trained using unsupervised learning to produce a low-dimensional (typically two-dimensional), discretized representation of the input space of the training samples, called a map, and is therefore a method to do dimensionality reduction.
• Self-organizing maps differ from other artificial neural networks as they apply competitive learning as opposed to error-correction learning (such as backpropagation with gradient descent), and in the sense that they use a neighbourhood function to preserve the topological properties of the input space.

Distribute each process to one less than maximum request resources i.e. 3(2 - 1) = 3

Total no. of resources = 3 + 1(additional resource for deadlock avoidance)

If total no. resources are greater than given resources then a deadlock will occur.

3 + 1 <= 4

4 <=4

Modulus of given counter is = 2^N = 2⁶ = 64.

In the OSI model, the seven layers from bottom to top are as follows: physical layer, data link layer, network layer, transport layer, session layer, presentation layer, the application layer.

Data-link layer:

• This layer is responsible for moving frames from one hop to next.
• The Data-link layer divides the stream of bits received from the network layer into manageable units called frames.
• It adds a header to the frame to define the sender and receiver of the frame.
• It provides a flow and error control mechanism.

Different networking devices and the layers on which they operate is given below:

The correct answer is The project manager

Key Points

• The project manager plays a pivotal role in continuous risk monitoring and control in a software project.
• While the project team members, risk management team, and project sponsor have their respective contributions to risk management, it is the project manager who is primarily accountable for ensuring the ongoing vigilance of risk monitoring and evaluating the effectiveness of risk responses.
• This includes adapting risk management strategies as the project evolves and new risks are identified.

The correct answer is option 2.

Concept:

GROUP BY:

The GROUP BY function is used to group rows of a table that contain the same values in a specified column.

The given data,

Student(Rno, name, Branch, Year)

Query:

Select branch, count(*)

from student

group by branch;

Explanation:

Step 1:

The query selects the whole table student.

Step 2:

It divides the rows of student tables into groups by brach column. It divides into 3 groups because the branch has three distinct values.

Step 3:

From that three groups, it selects the only branch name and counts the number of members in each branch. It prints the like below,

Hence the correct answer is option 2.

FIRST(A) = FIRST(s) ={a, b, ε}

FIRST(B) = FIRST(s) ={a, b, ε}

So,FIRST(A) = {a, b, ε} = FIRST(B)

FOLLOW(A) = {First of { bB}, FIRST of {aB}}

FOLLOW(A) = {a, b}

FOLLOW(B) = FOLLOW(S) ={FOLLOW(A), $}

FOLLOW(B) = FOLLOW(S) ={FOLLOW(A), $} ={a, b,$}

Now, the answer is

FOLLOW(A) = {a, b}

FOLLOW(B) = {a, b, $}

FIRST(A) = FIRST(s) ={a, b, ε}

FIRST(B) = FIRST(s) ={a, b, ε}

So,FIRST(A) = {a, b, ε} = FIRST(B)

FOLLOW(A) = {First of { bB}, FIRST of {aB}}

FOLLOW(A) = {a, b}

FOLLOW(B) = FOLLOW(S) ={FOLLOW(A), $}

FOLLOW(B) = FOLLOW(S) ={FOLLOW(A), $} ={a, b,$}

Now, the answer is

FIRST(A) = {a, b, ε} = FIRST(B)

EXPLANATION:

FIRST and FOLLOW:

Parsing Table:

Hence the answer is

E3: B → S

FIRST and FOLLOW:

Parsing Table:

Hence the answer is

E2: S → bAaB, S → ε

The correct answer is Indicating the scope of variables

Key Points

Quantifiers in first-order predicate logic are symbols that express the extent to which a statement is true. There are two main types of quantifiers:

• Universal Quantifier (∀): It is used to express that a certain statement is true for all values of a variable within a given domain. For example, ∀x P(x) asserts that the predicate P is true for every element x in the domain.
• Existential Quantifier (∃): It is used to express that there exists at least one value of a variable within a given domain for which a certain statement is true. For example, ∃x P(x) asserts that there is at least one element x in the domain such that the predicate P is true.

Quantifiers play a crucial role in indicating the scope of variables, specifying whether a statement holds universally or existentially over a particular set of elements. Therefore, option C is the correct answer.

1. Instance (A) refers to a specific collection of information stored at a particular moment in the database, hence matching with 4.
2. Schema (B) represents the overall design of the database, thus it matches with 2.
3. Metadata (C) is data about data, which corresponds to 1.
4. Data model (D) involves the allocation of conceptual tools to describe data and semantics, aligning with 3.

So, the correct matching is A-4, B-2, C-1, D-3.

((¬ p ∨ ¬ q) ∧ (p ∧ q)) ∨ r → p ∧ (q ∨ r)

≡ (¬ (p ∧ q) ∧ (p ∧ q)) ∨ r → p ∧ (q ∨ r)

∵ F ∧ T → F

(¬ (p ∧ q) ∧ (p ∧ q)) ∨ r → p ∧ (q ∨ r)

≡ F ∨ r → p ∧ (q ∨ r)

≡ r → p ∧ (q ∨ r)

Group Homorphisms :

Let (G,o) & (G’,o’) be 2 groups, a mapping “f ” from a group (G,o) to a group (G’,o’) is said to be a homomorphism

if –f(a o b) = f(a) o' f(b) for all a, b ∈ G

∴ option 1 is correct

Option 1 and Option 4:

C → B (It is not satisfied for given instance)

Option 2:

AC → B ((It is not satisfied for given instance))

Option 3:

AC → A

It is trivial dependency, and therefore this dependency is always satisfied.

B → C

Since B is unique for given instance, therefore this dependency is satisfied for given instance

Hence Option 3 is correct

The postfix expression is option 2 i.e. AB+C*DE/F*+

The correct answer is option 1.

Concept:

The given data,

The time taken for 600 characters = 1 minute.

i.e 60 seconds =600 characters.

1 second= 600/ 60 characters per second.

1 second =10 characters per second.

Note:

The baud rate is the rate at which information is transferred in a communication channel.

If one character stores in eleven bit then the transfer time of 11 bit is=?

11 bits = 11x time taken each bit

11 bits= 11 x 10 bauds

11 bits=110 bauds.

Hence the correct answer is 110 bauds.

Fuzzy logic:

• Fuzzy logic is a concept of certain degree. Boolean logic is a subset of fuzzy logic.
• Fuzzy logic is a form of many-valued logic which deals with reasoning that is approximate rather than fixed and exact.
• Compared to traditional binary sets (where variables may take on true or false values), fuzzy logic variables may have a truth value that ranges in degree between 0 and 1.
• It is employed to handle the concept of partial truth, where the truth value may range between completely true and completely false.
• It mimics human behaviour and deals with information, which is vague, imprecise, uncertain, ambiguous, inexact, or probabilistic

If the array is sorting is increasing or non-increasing order, choosing either first or last element given the worst-case time complexity in Quick Sort.

In every step of quick sort, numbers are divided as per the following recurrence.

T(n) = T(n - 1) + O(n)

A task environment is a theoretical construct which is supposed to supply the goal relevant consequences of allowable moves in performing the task. 

The time delay between two successive initiations of memory operation is Memory cycle time. The time is taken to finish one task and to start another. It is the time that is measured in nanoseconds, the time between one Ram access of time when the next Random Access Memory (RAM) access starts. That Cycle Time finds the right place for the memory to take place in the memory and transfer time of that information/process. So, one should not get confused while thinking about the Clock Cycle or Clock Speed which have to do with the number of cycles/second to which a processor is paced.

Loading a routine only when it is called Dynamic loading. Dynamic loading is a mechanism by which a computer program can, at run time, load a library (or other binary) into memory, retrieve the addresses of functions and variables contained in the library, execute those functions or access those variables, and unload the library from memory.

This is used to check the overflow that occurs in the operation. In computer processors, the overflow flag (sometimes called the V flag) is usually a single bit in a system status register used to indicate when an arithmetic overflow has occurred in an operation, indicating that the signed two's-complement result would not fit in the number of bits used for the result. Some architectures may be configured to automatically generate an exception on an operation resulting in overflow.

Tree algorithm is used to solve any kind of problem because specific variants of the algorithm embed different strategies. Much of the work on search in artificial intelligence deals with trees. These are usually defined implicitly by a so-called problem representation, and the process of searching for a solution of the given problem can be represented by a search tree (more generally an acyclic graph, because of transpositions).

The lexical analysis phase of compilation breaks the input text up into sequences of lexemes that each belongs to some particular token type that's useful in later analysis. Consequently, keywords are usually first recognized during lexical analysis in order to make parsing easier.

Reducing memory load means that users should not be required to memorize (or recall out of their heads) a great deal of information to carry out tasks. Memory load reduces users’ capacity to perform the main task. There are many instances where a user’s memory load can be reduced, such as:

• Disclose information in a progressive fashion
• Define intuitive shortcuts
• Recognition rather than recall
• Externalize information through visualization
• Hierarchical structure
• Default values
• Concrete examples
• Generic rules and actions
• Establish meaningful defaults.