ISC 2019 Computer Science Question Paper for Class 12

About this paper

This is ISC Class 12 Computer Science Paper 1 (Theory), code 868A, from the 2019 board examination. It carries 70 marks and three hours, plus fifteen minutes to read the paper. All of Part I, worth 20 marks, is compulsory. Part II, worth 50 marks, asks for two questions from each section. Section A is Karnaugh maps, to be drawn with NAND or NOR gates, together with a decoder and a half adder. Section B is Java: an Armstrong number, reversing each value in a matrix, and moving the vowels of a word to the front. Section C is inheritance, a queue of addresses, and a linked list or binary tree. Programs must be written in Java. This copy has the questions only.

Exam

ISC Class 12

Subject

Computer Science

Year

2019

Paper code

868A

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

12

Pages

10

Answers included

No, questions only

Paper pattern

• Part I

  20 marks

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

• Section A

  20 marks

  Questions 4–6, ten marks each; answer any two. Karnaugh maps using NAND or NOR gates, a decoder, a half adder and a bonus truth table

• Section B

  20 marks

  Questions 7–9, ten marks each; answer any two. Java classes for an Armstrong number, reversing matrix elements and bringing vowels forward

• Section C

  10 marks

  Questions 10–12, five marks each; answer any two. Inheritance for the highest mark, a queue of addresses, a linked list and a binary tree

Topics covered

• Boolean algebra and duality
• Karnaugh maps
• Decoders and half adders
• Propositional logic
• Interfaces
• Recursion and complexity
• Matrices
• Strings
• Inheritance
• Queues
• Linked lists and binary trees

Questions from this paper

1. Find the dual of X·Y + X·Y′ = X + 0.
2. Compare the complexities O(n) and O(2ⁿ) and state which is better, with a reason.
3. An Armstrong number equals the sum of its digits each raised to the power of the number of digits. 371 = 3³ + 7³ + 1³. Design a class ArmNum that uses recursion.
4. Class MatRev reverses every element of a matrix, so 72 becomes 27 and 371 becomes 173.
5. Class Rearrange moves the vowels of an uppercase word to the front, followed by the consonants. ORIGINAL becomes OIARGNL.
6. A Diary adds an address at the rear and removes one from the front. Specify pushadd and popadd, and name this entity.