The 15 one-mark questions from the March 2025 12th Standard Computer Science public exam, in paper order, with the correct option marked and a short explanation.
Q1
Which of the following is a distinct syntactic block?
- A. Subroutines
- B. Function
- C. DefinitionCorrect
- D. Modules
Explanation. A definition is a distinct syntactic block: it binds a name to a function or value and is written as a separate block of code.
Q2
Which of the following functions that build the abstract data type?
- A. ConstructorsCorrect
- B. recursive
- C. Destructors
- D. Nested
Explanation. Constructors are functions that build (create) an abstract data type; selectors retrieve information from it.
Q3
The __________ rule is used to decide the order in which the scopes are to be searched.
- A. LBEG
- B. LEGBCorrect
- C. GEBL
- D. GBLE
Explanation. Python searches scopes in the LEGB order: Local, Enclosed, Global, Built-in.
Q4
Binary search is also called as __________.
- A. Random search
- B. Linear search
- C. Half-interval searchCorrect
- D. Sequential search
Explanation. Binary search repeatedly halves the search interval of a sorted list, so it is also called half-interval search.
Q5
Which operator is also called as conditional operator?
- A. Logical
- B. TernaryCorrect
- C. Assignment
- D. Relational
Explanation. The ternary operator (x if condition else y) chooses a value based on a condition, so it is called the conditional operator.
Q6
Which of the following is known as definite loop?
- A. forCorrect
- B. do...while
- C. if...else
- D. while
Explanation. A for loop runs over a known range or sequence, so the number of iterations is fixed in advance; hence it is a definite loop.
Q7
Which of the following keyword is used to exit a function block?
- A. finally
- B. define
- C. def
- D. returnCorrect
Explanation. The return statement ends the execution of a function and sends control (and optionally a value) back to the caller.
Q8
The subscript of a string may be:
- A. positive or negative numbersCorrect
- B. positive numbers
- C. both positive and negative numbers
- D. negative numbers
Explanation. A string subscript can be a positive index (from 0, left to right) or a negative index (from -1, right to left). Options (a) and (c) mean nearly the same; the textbook answer is (a).
Q9
Which of the following is the output of the given Python code?
str1="Computer Science"
print(str1[::-1])
- A. ecneicS retupmoCCorrect
- B. Computer Science
- C. eniS eumC
- D. Cmue Sine
Explanation. The slice [::-1] uses step -1, so it returns the whole string in reverse order: "ecneicS retupmoC".
Q10
Class members are accessed through which operator?
- A. #
- B. &
- C. %
- D. .Correct
Explanation. Class members are accessed with the dot operator, for example object.member.
Q11
Who developed ER model?
- A. Chend
- B. ChenCorrect
- C. Chand
- D. E F Codd
Explanation. The Entity-Relationship (ER) model was developed by Peter Chen in 1976; E F Codd proposed the relational model.
Q12
Queries can be generated using:
- A. MODIFY
- B. SELECTCorrect
- C. ALTER
- D. ORDER BY
Explanation. A query that retrieves data from tables is written with the SELECT command; ORDER BY is only a clause of SELECT, and ALTER changes the table structure.
Q13
Making some changes in the data of the existing file or adding more data is called:
- A. Modification
- B. Editing
- C. Alteration
- D. AppendingCorrect
Explanation. Opening an existing CSV file in append mode ("a") and adding more data to it is called appending.
Q14
The module which allows to interface with the Windows operating system is:
- A. csv module
- B. OS moduleCorrect
- C. getopt module
- D. sys module
Explanation. The OS module provides functions to interact with the operating system, such as os.system() to run the compiler and the executable.
Q15
Which of the following keyword avoids the duplicate?
- A. Where
- B. DistinctCorrect
- C. GroupBy
- D. Remove
Explanation. The DISTINCT keyword used with SELECT removes duplicate rows from the result.
About this paper
These are the Part I one-mark multiple-choice questions from the March 2025 12th Standard Computer Science public examination conducted by the Tamil Nadu Directorate of Government Examinations. The answers and explanations are prepared by TN Online Test for revision. Each question links to the textbook chapter it comes from, so you can go back to that chapter's notes and MCQs.
