Computer Science: CUET Mock Test - 5 - CUET MCQ

The correct answer is List of strings

Key PointsThe readlines() method of the file object in Python returns a list of strings. (Option 3)

• Opening the File: You use the open() function to open a file in read mode ("r"). This creates a file object that represents the open file.
• Calling readlines(): You call the readlines() method on the file object. This method reads the entire contents of the file line by line, treating each line as a separate string.
• Returning the List: The readlines() method returns a list where each element in the list is a string representing a line from the file. The newline character (\n) is typically included at the end of each line in the list.

The correct answer is 48 bits

Key Points

• The MAC address is a unique 12-digit hexadecimal numbers (48 bits in length) hardware address associated with a network adapter card, which is engraved on NIC at the time of manufacturing.
• The can be physically identified on the network using its MAC address is a permanent address and cannot be changed under any circumstances it means two devices cannot have the same MAC address.
• It is 12-digit hexadecimal numbers (48 bits in length) format on each device and is represented by Colon-Hexadecimal notation.
• Example: 00:0b:45:9e:87:46.

The correct answer is A and D only

Key Points

• A. % represents zero, one, or multiple characters
  • This is correct. The percent sign (%) is a wildcard that can match any sequence of characters, including an empty string (zero characters).
• B. Underscore represents zero, one, or multiple characters
  • This is incorrect. The underscore (_) represents exactly one character, not zero or multiple characters.
• C. Underscore represents only multiple characters
  • This is incorrect for the same reason as B. The underscore represents only one character.
• D. Underscore represents exactly a single character
  • This is correct. The underscore always matches exactly one character in the pattern.
• E. % represents zero characters
  • This is partially correct. While the percent sign can match zero characters, it can also match one or more characters, so this statement doesn't fully capture its functionality.

Therefore, the only correct statements are A and D, making option 1 the right choice.

The correct answer is Star

Key PointsNetwork topology refers to how the nodes and links in a network are arranged. A network node is a device that can send, receive, store, or forward data. A network link connects nodes and may be either cabled or wireless links.

• Understanding topology types provides the basis for building a successful network. There are a number of topologies but the most common are bus, ring, star, and mesh:

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1. A bus network topology is when every network node is directly connected to the main cable.
2. In a ring topology, nodes are connected in a loop, so each device has exactly two neighbors. Adjacent pairs are connected directly; non-adjacent pairs are connected indirectly through multiple nodes.
3. In a star network topology, all nodes are connected to a single, central hub and each node is indirectly connected through that hub.
4. A mesh topology is defined by overlapping connections between nodes. You can create a full mesh topology, where every node in the network is connected to every other node. You can also create a partial mesh topology in which only some nodes are connected to each other and some are connected to the nodes with which they exchange the most data. Full mesh topology can be expensive and time-consuming to execute, which is why it's often reserved for networks that require high redundancy. Partial mesh provides less redundancy but is more cost-effective and simpler to execute.
5. A tree topology is a special type of structure where many connected elements are arranged like the branches of a tree. For example, tree topologies are frequently used to organize the computers in a corporate network or the information in a database.

The correct answer is option 4.

Concept:

Infix:

An infix expression prints the operand 1, operator, and operand 2 respectively.

Postfix:

A Postfix expression prints the operand 1, operand 2, and operator respectively.

Prefix:

A Prefix expression prints the operator operand 1, and operand 2 respectively.

Converse postfix:

A converse postfix expression prints the operand 2, operand 1, and operator respectively.

Converse infix:

A converse infix expression prints the operand 2, operator, and operand 1 respectively.

Converse prefix:

A converse prefix expression prints the operator, operand 2, and operand 1 respectively.

Explanation:

The given infix is,

(a+(b/c) *(d^e)-f)

() is highest prority

The inner (b/c) is excutes first,

operand 1=b

operand 2=c

Operator= /

(a+/bc *(d^e)-f)

The inner (d^e) is excutes next,

operand 1=d

operand 2=e

Operator= ^

(a+/bc *^de-f)

The highest operator is * than +, -

operand 1=/bc

operand 2=^de

Operator= *

(a+*/bc^de-f)

The highest operator is + than -.

operand 1=a

operand 2= */bc^de

Operator= +

(+a*/bc^de-f)

operand 1=+a*/bc^de

operand 2= f

Operator= There is no start phase in Virus Life Cycle.

The prefix is -+a*/bc^def.

Hence the correct answer is -+a*/bc^def.

The correct answer is B and D only

Key Points

• A. While certain implementations of SQL may be case-sensitive for identifiers (e.g., table or column names), the SQL language itself is not inherently case-sensitive, especially for its keywords (e.g., SELECT, FROM, WHERE), making statement A misleading/false.
• B. SQL allows for the creation of views and tables, enabling structured storage and targeted data access, making statement B true.
• C. SQL is specifically designed for handling data in relational database management systems (RDBMS), giving it powerful functionality for data management, making statement C false.
• D. Constraints (PRIMARY KEY, FOREIGN KEY, UNIQUE, NOT NULL, CHECK) are a fundamental aspect of ensuring data integrity within an SQL database, making statement D true.

Hence, the correct answer is 2) B and D only.

The correct answer is Field

Key Points

• Report:
  • A report in the context of a database represents a formatted and organized presentation of data.
  • Reports may be generated from database information, often following a user-specified query, to present data in a way that is easy to understand.
  • They typically gather data from multiple fields and records, often across different tables.
• Field:
  • A field represents the smallest unit of data in a database. It holds only one specific type of information.
  • In a table, a field corresponds to a column. For instance, in a database table that stores employee data, you might have fields such as "EmployeeID", "FirstName", "LastName", "Email", each of which holds one specific type of information.
• File:
  • In a database, a file is a collection of related records. In older, file-based databases this was a more common term.
  • In modern, relational databases, we commonly refer to such a collection of records as a table. These contain multiple types of information as they consist of multiple fields.
• Record:
  • A record represents a single unit of related data fields in a database. In a table, a record corresponds to a row.
  • For instance, each employee within an "Employees" table would have their own record, and this record would contain multiple types of information (the employee's ID, name, email, etc.), each stored in its own field.

The correct answer is Age

Key PointsAn atomic attribute is an attribute that cannot be divided any further. From the options provided:

• Date of birth: Not atomic, as it can be divided into day, month, and year.
• Telephone number: Not atomic, Telephone Numbers begin with the area code, then one digit for the operator code, then six digits for the primary telephone number.
• Name: Not atomic, as it can be divided into first name and last name.
• Age: Generally considered atomic, as it is usually represented as a single numerical value.

So, the atomic attributes from the given options are: 4) Age

The correct answer is option 3.

Concept:

The SQL order of execution specifies the order in which query clauses are executed. Some of the most common query issues might be easily avoided if people had a better understanding of the SQL order of execution, often known as the SQL order of operations.

Order or SQL query evaluation:

1. From: Cartesian product of tables.
2. Where: Select the rows.
3. Group by: Divide the rows into groups.
4. Having: Select the groups.
5. Expressions: Expressions In select are evaluated.
6. Distinct: Distinct in select (Eliminate the duplicates).
7. Ser-Operations: (Union, intersect, Except)
8. Order By: Sort the rows.

Hence the correct answer is Where, Having, Distinct, Order By.

" .py " is the correct extension of the Python file.
.PY file is a program or script written in Python, which is an interpreted object-oriented programming language. It may be written in a text editor and may be edited, but it must be run using a Python interpreter. .PY files are often used to program web servers and other administrative computer systems.

Primary key is a key that uniquely identifies each record in a table.
Foreign key is used to establish a relationship between two tables.
Candidate key can be used as a primary key and is unique for each record.
Composite key is composed of two or more columns and is used to uniquely identify each record in a table.

A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions on the Internet. Data sent through the internet, such as a web page or email, is in the form of data packets.

The 'readline()' function can be used to read the first line of a text file Myfile. txt. Hence, the correct answer is option 3.

The "a" mode allows you to open a file to append some content to it. If we want to add a new line to it, we can open it using the "a" mode (append) and then, call the write() method, passing the content that we want to append as argument.

ALTER TABLE statement is used to add a new column to an existing table in SQL. INSERT ROW statement is not used to insert the Row to an existing table in SQL. INSERT INTO is used to insert the Row.

Concept of slicing is used in this question. In string slicing, the output is the substring starting from the first given index position i.e. 2 to one less than the second given index position i.e. (8 - 1 = 7) of the given string str1. Hence, the output will be "format".

The process of identifying a slot for the second and further items in the hash table in the event of collision, is called collision resolution.

Yes, All (1), (2) and (3) are the advantages of a database management system.

The binary heap data structure takes O(n) time to build, and the repeated extraction and placement operations take O(log n) time. Hence, the total worst-case time complexity of Heap Sort is O(n log n).

• Selection Sort: O(n²) - This occurs when the array is in reverse sorted order or any other order, as the algorithm has to traverse the entire array to find the minimum element repeatedly.
• Radix Sort: O(nk), where n is the size of the array and k is the number of digits in the largest number.
• Count Sort: O(n+k), where n is the number of elements to be sorted, and k is the range of input values.

In Python, any non-zero value is considered True. So, it will evaluate to true.

r mode is used to open the file.
'NewsLetter.TXT'. It opens a file in reading mode.

• (A) Correct – Domain represents the set of all valid values an attribute can hold.
• (B) Correct – A relation is represented as a table in the relational model.
• (C) Correct – A Superkey uniquely identifies tuples, while a Candidate Key is a minimal Superkey.
• (D) Incorrect – A Foreign Key refers to a key from another table, not the same table.

Thus, the correct option is (2) (A), (B), and (C) only.

line.split( ) method fits the blank in Statement-3 to read data word by word.

file.close( ) is used to close the file. It is important to close the file as soon as you have finished your work with the file.

file.read( ) is fits the blank in Statement-2 as this method returns a string containing all characters in a file.

len(c)<4 is used fits the blank in Statement-4, which displays the word having lesser than 4 characters.

Concept:
The range of frequencies available for data transmission is known as Bandwidth. It is also the amount of data that can be transmitted in a fixed amount of time.

• The bandwidth of digital equipment is commonly measured in bits per second or bytes per second. The bandwidth of analog devices is measured in cycles per second, or HZ.
• Digital bandwidth, or simply bandwidth, is the quantity of data that can be transported from one point to another in a given length of time in computer networks and computer science.
• The range of frequencies filled by a modulated radio-frequency signal is known as bandwidth in electronics, and it is commonly expressed in hertz or as a percentage of the radio frequency.
• The effective bandwidth multiplied by the frequency reuse factor equals the channel bandwidth, where the effective bandwidth is the operating bandwidth correctly scaled by the uplink/downlink ratio.
• The main distinction between the two is that frequency refers to the rate at which a radio signal sends and receives communication signals, whereas bandwidth refers to the difference between the signal's highest and lowest frequencies.

In the event of a failure, database recovery is the process of restoring the database to a correct (consistent) state.

Three states of database recovery:

• Pre-condition: At any given point in time the database is in a consistent state.
• Condition: Occurs the same kind of system failure.
• Post-condition: Restore the database to the consistent state that existed before the failure.

Statement (A) is correct: SQL is used to define, manipulate, and query data efficiently in databases.
Statement (B) is correct: SQL is divided into DDL (Data Definition Language), DML (Data Manipulation Language), DQL (Data Query Language), and DCL (Data Control Language).
Statement (C) is incorrect: SELECT belongs to DQL, not DML. DML includes INSERT, UPDATE, and DELETE, which modify data.
Statement (D) is incorrect: SQL is not a procedural programming language; it is a declarative language, meaning users specify what they want, not how to do it.

The correct answer is option 3.

Concept:
print() method:
The print() method outputs the message supplied to the screen or another standard output device. The message can be a string or any other object, which will be transformed into a string before being displayed on the screen.

Syntax:
print(object(s), sep=separator, end=end, file=file, flush=flush)

Explanation:
The given python code is,
print("Hello world"):
The print function prints the data which are there in double-quotes and give the output is Hello world.
print('Hello world'):
The print function prints the data which are there in single quotes and gives the output is Hello world. And python accepts either double quotes or single quotes.
print('\"Hello world'):
The print function prints the data which are there in single quotes and gives the output as "Hello world. \ back ward slash emits after the single or double quotes in the print function.
Hence the correct answer is 
Hello world
Hello world
"Hello world