CBSE 2015 Computer Science Question Paper for Class 12

About this paper

This is the CBSE Class 12 Computer Science paper from the 2015 board examination, code 91/1 (Series SSO/1, Set 4). It carries 70 marks over three hours and has 11 questions. Students attempt either Section A, written for C++, or Section B, written for Python; each covers programming concepts, data structures and file handling across four questions. Section C is compulsory for everyone and covers database concepts with SQL queries on DEPT and WORKER tables, Boolean algebra with a K-map reduction, and networking, ending with a case study on setting up a network for an educational organisation's Chennai campus and Delhi head office. This copy has the questions only, without solutions.

Exam

CBSE Class 12

Subject

Computer Science

Year

2015

Paper code

91/1

Maximum marks

70

Time allowed

3 hours

Questions

11

Pages

17

Answers included

No, questions only

Paper pattern

• Section A

  Questions 1–4 for C++ candidates: C++ basics and output questions, classes, constructors and inheritance, arrays and stacks, and data file handling

• Section B

  Questions 1–4 for Python candidates: Python basics and output questions, classes and exceptions, sorting, searching and stacks, and file handling

• Section C

  Questions 5–7, compulsory for all: SQL and keys, Boolean algebra, and communication and network concepts

Topics covered

• C++ programming and output questions
• Classes, constructors and destructors
• Inheritance
• Arrays and address calculation
• Stacks and infix to postfix conversion
• Data file handling
• Python classes and exception handling
• Sorting and binary search
• Database concepts and SQL
• Boolean algebra and K-maps
• Networking and cyber crime

Questions from this paper

1. What is a copy constructor? Give a suitable example in C++, with its definition within a class and the declaration of an object with its help.
2. A two-dimensional array P[20][50] is stored in memory along the row, with each element occupying 4 bytes. Find the address of the element P[10][30] if the element P[5][5] is stored at memory location 15000.
3. Write a method in Python to search for a value in a list sorted in ascending order using binary search. It should return −1 if the value is not present, or else the position of the value in the list.
4. Verify the following using Boolean laws: X + Y' = X.Y + X.Y' + X'.Y'
5. What is a worm? How is it removed?
6. Differentiate between ftp and http.