100 Important Questions – Class XI Computer Science Unit 2: Computational Thinking and Programming–1

Problem solving is the systematic process of understanding a problem and developing a suitable solution for it.

An algorithm is a finite sequence of clear and step-by-step instructions used to solve a problem.

Analysing the problem, developing an algorithm, coding, testing and debugging.

Decomposition is the process of breaking a complex problem into smaller and manageable sub-problems.

A flowchart is a graphical representation of an algorithm using standard symbols and arrows.

Pseudocode is an informal description of an algorithm written using simple language and programming-like statements.

It provides a logical sequence of steps and helps the programmer understand the solution before writing code.

Testing involves executing a program with suitable inputs to check whether it produces the expected output.

Debugging is the process of identifying and correcting errors in a program.

Smaller problems are easier to understand, solve, test and debug.

Python is a high-level, interpreted, general-purpose programming language.

Python was developed by Guido van Rossum.

Python has simple syntax and is platform independent.

Interactive Mode allows Python statements to be entered and executed one at a time at the Python prompt.

Script Mode allows a complete Python program to be written in a file and executed as a program.

It is the set of characters that can be used to write Python programs, including letters, digits, special symbols and whitespace characters.

A token is the smallest individual unit of a Python program recognised by the interpreter.

Keywords, identifiers, literals, operators and punctuators.

An identifier is a name given to variables, functions, classes or other program elements.

No. An identifier cannot start with a digit.

Yes. An underscore can be used in an identifier.

No. An identifier cannot begin with a digit.

Keywords are reserved words in Python that have predefined meanings, such as if, else, for and while.

No. Keywords are reserved and cannot be used as identifiers.

A literal is a fixed value directly written in a Python program, such as 25, 3.14 or "Python".

A variable is a named reference used to store a value during program execution.

An L-value refers to an object or variable that can appear on the left side of an assignment.

An R-value is the value or expression placed on the right side of an assignment.

Comments explain the program and improve readability. They are ignored by the interpreter.

A data type specifies the kind of value stored by a variable and the operations that can be performed on it.

int.

float.

A complex number contains a real part and an imaginary part, for example 3+4j.

True or False.

A string is a sequence of characters enclosed in quotes.

A list is an ordered and mutable collection of elements.

A tuple is an ordered and immutable collection of elements.

A dictionary is a mutable collection of key-value pairs.

An operator is a symbol or keyword used to perform an operation on one or more operands.

+, -, *, /, //, % and **.

/ performs true division, while // performs floor division.

It returns the remainder after division.

They compare two values and return a Boolean result.

and, or and not.

They combine an operation with assignment, such as +=, -=, *= and /=.

is and is not are identity operators used to check object identity.

in and not in are membership operators used to test whether a value belongs to a sequence or collection.

Operator precedence determines the order in which operators are evaluated in an expression.

An expression is a combination of values, variables, operators and function calls that produces a result.

A statement is an instruction that Python can execute.

The input() function.

It returns a string.

The print() function.

Type conversion is the process of converting a value from one data type to another.

Explicit conversion is performed by the programmer using functions such as int(), float() and str().

Implicit conversion is automatically performed by Python when required for compatible operations.

A syntax error occurs when the rules or grammar of Python are violated.

A logical error occurs when a program runs successfully but produces an incorrect result.

A runtime error occurs while a program is executing, such as division by zero.

Flow of control refers to the order in which statements of a program are executed.

In sequential flow, statements are executed one after another in their written order.

A conditional statement executes different blocks of code depending on whether a condition is true or false.

if, if-else and if-elif-else.

Indentation defines blocks of code and is essential for Python's syntax and program structure.

Iteration means repeatedly executing a block of statements.

for loop and while loop.

It is generally used when iterating over a sequence or a known range of values.

It is used when a block should continue executing as long as a specified condition remains true.

It generates a sequence of numbers commonly used with for loops.

It immediately terminates the nearest enclosing loop.

It skips the remaining statements of the current iteration and moves to the next iteration.

A nested loop is a loop placed inside another loop.

A string is an ordered sequence of characters enclosed within quotes.

Indexing is the process of accessing individual characters of a string using their positions.

Indexing starts from 0.

Slicing is used to extract a portion of a string using a range of indices.

Concatenation means joining two or more strings using the + operator.

String repetition means repeating a string multiple times using the * operator.

A list is an ordered and mutable collection of elements, written using square brackets.

List slicing extracts a portion of a list using a range of indices.

A tuple is an ordered and immutable collection of elements, generally written using parentheses.

Because its elements cannot be changed after the tuple has been created.

Tuple assignment allows multiple variables to receive multiple values in a single statement.

a, b, c = 10, 20, 30

A key is a unique identifier used to access a corresponding value in a dictionary.

student["name"]

A value can be accessed using its corresponding key.

A module is a Python file containing reusable functions, variables or classes.