Computer Science: CUET Mock Test - 4 - CUET Humanities MCQ

A primary key is a field or set of fields in a table that uniquely identifies each record in the table and cannot be Null. It is used to enforce data integrity and to ensure that there are no duplicate records in the table. A foreign key is a field in one table that refers to the primary key in another table. It is used to establish a relationship between two tables, and it ensures that data in one table is linked to data in another table.

A variable can have a short name (like x and y) or a more descriptive name (age, carname, total_volume).

(A) MQTT is a lightweight, publish-subscribe protocol that is ideal for low-bandwidth, high-latency networks, making it well-suited for IoT devices that operate in remote areas with limited connectivity.
(B) CoAP is a lightweight protocol designed for constrained devices and low-power networks, making it well-suited for IoT devices that operate on battery power or have limited processing capabilities.
(C) HTTP is a popular protocol used for web-based communication, but it is not as well-suited for IoT devices due to its high overhead and lack of support for low-power networks.
(D) LoRaWAN is a long-range, low-power protocol designed for IoT devices that need to communicate over long distances, making it well-suited for applications like smart agriculture or asset tracking.

Data Definition Language: The SQL DDL provides commands for defining relation schemas, deleting relations, and modifying relation schemas.

In relational model, data is stored in relations (tables) and is represented in form of tuples (rows). RDBMS is used to manage relational database. Relational database is a collection of organized set of tables related to each other, and from which data can be accessed easily.

In a DBMS, the SQL database language is used to:
Create the database and table structures
Perform basic data management chores (add, delete and modify)
Perform complex queries to transform raw data into useful information

• A subquery is a query that is nested inside another query and is used to retrieve data to be used in the main query.
• A 'Common Table Expression' (CTE) is a named temporary result set that can be used within a query. It is similar to a subquery but is declared separately and can be referenced multiple times within the same query.
• A window function is a function that performs a calculation across a set of rows that are related to the current row. It is used to calculate values such as running totals or moving averages.
• A materialized view is a physical copy of a query result that can be stored and queried later. It is used to improve performance by precomputing expensive queries.

Bubble sort is a simple sorting algorithm that compares adjacent elements and swaps them if they are in the wrong order. It has a worst-case time complexity of O(n^2) for both comparisons and swaps, making it inefficient for large collections. Merge sort is a divide-and-conquer sorting algorithm that works by dividing the collection into smaller subcollections, sorting them recursively, and then merging the sorted subcollections to produce the final sorted collection. It has a worst-case time complexity of O(n log n) for both comparisons and swaps, making it efficient for large collections.

while(0) - It is opposite of while(1). It means condition will always be false and ,thus, the code in 'while' will never get executed.

Each character is encoded in the ASCII or Unicode character. So, we can say that Python strings are also called the collection of Unicode characters. In Python, strings can be created by enclosing the character or the sequence of characters in the quotes.

Underflow occurs when the user performs a pop operation on an empty stack.

Instance or extension or database state which is a collection of information stored in a database at a particular moment is called an instance of the database. Thus, it is a dynamic value which keeps on changing.

(A) World Wide Web (WWW) - It is a system of interlinked hypertext documents that are accessed via the Internet. Documents and downloadable media are made available to the network through web servers and can be accessed by programs such as web browsers.
(B) Internet - The Internet, sometimes called simply "the Net," is a worldwide system of computer networks. It is a network of networks in which users at any one computer can, if they have permission, get information from any other computer. Hence, it is a global network of interconnected computers and other devices that use standardized communication protocols.
(C) Cloud Computing - It is a model for delivering on-demand access to shared computing resources over the Internet. It is the delivery of computing services—including servers, storage, databases, networking, software, analytics, and intelligence—over the internet to offer faster innovation and flexible resources.
(D) Machine-to-Machine (M2M) - It is technology that enables direct communication between IoT devices, without the need for human intervention. The main purpose of M2M technology is to tap into sensor data and transmit it to a network.

Linear Search has a worst-case time complexity of O(n), where n is the size of the input data.
Binary Search has a worst-case time complexity of O(log n), where n is the size of the input data.
Interpolation Search has a worst-case time complexity of O(n log n), which is less efficient than O(log n) algorithms like Binary Search.
The worst-case running time of Depth-First Search (DFS) depends on the graph being traversed. In a graph with n nodes and m edges, the time complexity of DFS is O(n+m), which means that the running time increases linearly with the number of nodes and edges in the graph.

We can use * operator to repeat the tuple values n number of times.
For example:
("abc",)*3 will return ('abc', 'abc', 'abc').

Wireless Access Points are networking devices that allow Wi-Fi devices to connect to a wired network. They form wireless local-area networks. An access point acts as a central transmitter and receiver of wireless radio signals.

Pickle in Python is primarily used in serializing and deserializing a Python object structure. In other words, it's the process of converting a Python object into a byte stream to store it in a file/database, maintain program state across sessions, or transport data over the network.

A file which is not existing cannot be opened for reading. When we open an existing file for writing, the existing file will be opened. If the file is not existing, then it will be created. The existing file will be overwrittten with the new contents. So, we have to open an existing file in the 'append' mode.

The readline() method returns one line from the file.
The writerow method writes a row of data into the specified file.
Read () is not a function method of csv module in Python.

A CSV file is a comma-separated file that uses a coma as its delimiter.
CSV files are used to store data in a table format commonly used for e-commerce data storage.
We need to suppress the EOL (End Of Line) translation in CSV files.
Because with EOL translation, it's not possible to use CSV files on another platform, so it only allows perform on the created platform.
If you add a newline argument in the creation of a CSV file, that argument will write a CSV file with no EOL.
By suppressing the EOL, the CSV file can be used on any platform.

'val' is not a keyword in python language. All the other options are correct keywords used in python language.

SEQUEL later became SQL (still pronounced "sequel"). In 1979, Relational Software, Inc. (now Oracle) introduced the first commercially available implementation of SQL. Today, SQL is accepted as the standard RDBMS language.

The correct way to call a function is my_func().

USE DatabaseName;
The database name should always be unique within the RDBMS.

Function Name and Parameter List are parts of a function header in python.

Internet is a global system because it interconnects the networks worldwide.

Python file method seek() sets the file's current position at the offset. The whence argument is optional and defaults to 0, which means absolute file positioning; other values are 1, which means seek relative to the current position, and 2, which means seek relative to the file's end. There is no return value.

Unstructured data offers more flexibility and scalability. The absence of the pre-defined purpose of unstructured data makes it super flexible as the information can be stored in various file formats. Yet, this data is subjective and more difficult to work with. CSV helps into organize a huge amount of data in a proper and systematic way.

The map() method in Python preserves the order of items in the input iterable, and applies the given function to each item in that order. Therefore, the order of items in the output of the map() method is the same as the order in the input iterable. The order of items in the output of the map() method in Python is not sorted in ascending order.

Stacks are dynamic data structures that follow the Last In First Out (LIFO) principle. The last item to be inserted into a stack is the first one to be deleted from it.