The 15 one-mark questions from the March 2023 12th Standard Computer Science public exam, in paper order, with the correct option marked and a short explanation.
Q1
__________ members are accessible from outside the class.
- A. Secured members
- B. Public membersCorrect
- C. Private members
- D. Protected members
Explanation. In Python, variables defined in a class without a double-underscore prefix are public and can be accessed from outside the class; private members (prefixed with __) cannot be accessed directly.
Q2
Which of the following is not a keyword in Python ?
- A. continue
- B. break
- C. operatorCorrect
- D. while
Explanation. continue, break and while are reserved keywords in Python; "operator" is only the name of a standard library module, not a keyword.
Q3
The small sections of code that are used to perform a particular task is called :
- A. Pseudo code
- B. SubroutinesCorrect
- C. Modules
- D. Files
Explanation. Subroutines are small sections of code that perform a particular task and can be used repeatedly in a program.
Q4
The number of important control structures in Python :
- A. 5
- B. 3Correct
- C. 6
- D. 4
Explanation. Python has three important control structures: sequential, alternative (branching) and iterative (looping).
Q5
Class members are accessed through __________ operator.
- A. #
- B. &
- C. %
- D. .Correct
Explanation. Class members are accessed using the dot (.) operator, as in object_name.member_name.
Q6
The database Model which represents the Parent-Child relationship :
- A. HierarchicalCorrect
- B. Relational
- C. Object
- D. Network
Explanation. The hierarchical model stores data in a tree structure where each child record has only one parent, representing a parent-child relationship.
Q7
The operator which is used for concatenation ?
- A. *
- B. +Correct
- C. =
- D. &
Explanation. In Python the + operator joins two strings, e.g. "Hello" + "World" gives "HelloWorld"; * is used for repetition.
Q8
Importing C++ program in a Python program is called __________.
- A. Interconnecting
- B. WrappingCorrect
- C. Parsing
- D. Downloading
Explanation. Importing a C++ program into a Python program is called wrapping: the C++ code is wrapped so that it can be called from Python.
Q9
__________ command is used to remove a table from the database.
- A. DELETE ALL
- B. DROP TABLECorrect
- C. ALTER TABLE
- D. DELETE
Explanation. DROP TABLE removes the whole table (structure and data) from the database; DELETE only removes rows and ALTER TABLE changes the structure.
Q10
The function that returns the largest value of the selected column is :
- A. HIGH ()
- B. MAX ()Correct
- C. MAXIMUM ()
- D. LARGE ()
Explanation. The SQL aggregate function MAX() returns the largest value of the selected column; HIGH(), MAXIMUM() and LARGE() are not SQL functions.
Q11
The datatype whose representation is known are called :
- A. Concrete datatypeCorrect
- B. Built-in datatype
- C. Abstract datatype
- D. Derived datatype
Explanation. A concrete data type is one whose representation (implementation) is known; an abstract data type hides its representation.
Q12
A Function which calls itself, is called as :
- A. Lambda
- B. Built-in
- C. Return statement
- D. RecursionCorrect
Explanation. A function that calls itself is a recursive function, and the process is called recursion.
Q13
The mode which is used when dealing with non-text files like image or exe files :
- A. xls mode
- B. Text mode
- C. csv mode
- D. Binary modeCorrect
Explanation. Non-text files such as images or exe files are opened in binary mode (for example "rb" or "wb"), which returns bytes instead of strings.
Q14
In dynamic programming, the technique of storing the previously calculated values is called :
- A. MemoizationCorrect
- B. Saving value property
- C. Mapping
- D. Storing value property
Explanation. Memoization stores the results of already solved subproblems so they need not be calculated again in dynamic programming.
Q15
Let set A={3, 6, 9}, set B={1, 3, 9}.
The result of the following snippet Print (set A|set B)
- A. {1}
- B. {3, 6, 9, 1, 3, 9}
- C. {1, 3, 6, 9}Correct
- D. {3, 9}
Explanation. The | operator gives the union of two sets: all elements of both sets without duplicates, so A|B = {1, 3, 6, 9}.
