ISC 2017 Computer Science Question Paper for Class 12

About this paper

This is ISC Class 12 Computer Science Paper 1 (Theory), code 868A, from the 2017 board examination. It carries 70 marks and three hours, plus fifteen minutes to read the paper. Part I is compulsory and worth 20 marks, with Boolean laws, Java interfaces, an array address and a recursive method. Part II is worth 50 marks, and two questions are chosen from each of three sections. Section A is Karnaugh maps, combinational circuits and a half adder. Section B asks for Java classes: a palindrome number, addition of two times, and rearranging the letters of a word. Section C is inheritance for a sale with tax and fine, a queue of integers, and a linked list or binary tree. This copy has the questions only.

Exam

ISC Class 12

Subject

Computer Science

Year

2017

Paper code

868A

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

12

Pages

9

Answers included

No, questions only

Paper pattern

• Part I

  20 marks

  Questions 1–3, all compulsory: Boolean laws, Java concepts and a recursive dry run

• Section A

  20 marks

  Questions 4–6, ten marks each; answer any two. Karnaugh maps, an essay-competition truth table, a half adder and a multiplexer

• Section B

  20 marks

  Questions 7–9, ten marks each; answer any two. Java classes for a palindrome number, adding two times and sorting the letters of a word

• Section C

  10 marks

  Questions 10–12; answer any two. Sales inheritance, a queue of 100 integers, a linked list and a binary tree

Topics covered

• Boolean algebra
• Karnaugh maps
• Half adder and multiplexer
• Propositional logic
• Interfaces and constructors
• Recursion and complexity
• Matrices
• Strings
• Inheritance
• Queues
• Linked lists and binary trees

Questions from this paper

1. State the law represented by P ∨ P = P and prove it with a truth table.
2. State the Principle of Duality.
3. What does magicfun return for n = 7 and for n = 10? While n is not 0 it returns magicfun(n / 2) × 10 + (n % 2).
4. Class Palin tests whether a positive number equals its reverse, finding the reverse by recursion.
5. Class Adder adds two times stored as hours and minutes. 6 hours 35 minutes plus 7 hours 45 minutes is 14 hours 20 minutes.
6. Subclass Sales adds service tax at 12.4% of the sale amount, and a fine of 2.5% if the retailer pays more than 30 days late.