ISC 2026 Computer Science Improvement Examination Question Paper for Class 12

About this paper

This is the ISC Class 12 Computer Science Paper 1 (Theory) from the 2026 Improvement Examination, code 1226-868A-IE. It carries 70 marks and runs for three hours, with an extra fifteen minutes for reading only. There are eleven questions. Part I, worth 20 marks, is compulsory: ten one-mark items on Boolean algebra, propositions and Java, then short problems on an infix expression, a two-dimensional array, a recursive method and a Niven number. Part II is worth 50 marks. Candidates answer any two questions from Section A on logic circuits, any two from Section B on Java programs, and any two from Section C on a queue, inheritance, a linked list and a binary tree. Programs must be written in Java. This copy has the questions only.

Exam

ISC Class 12

Subject

Computer Science

Year

2026

Paper code

1226-868A-IE

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

11

Pages

12

Answers included

No, questions only

Paper pattern

• Part I

  20 marks

  Questions 1 and 2, compulsory. Question 1 has ten one-mark parts; Question 2 has short problems on notation, arrays and Java methods

• Part II, Section A

  20 marks

  Questions 3–5 on Boolean algebra and logic circuits; answer any two, 10 marks each

• Part II, Section B

  20 marks

  Questions 6–8, Java programs; answer any two, 10 marks each

• Part II, Section C

  10 marks

  Questions 9–11 on a queue, inheritance, a linked list and a binary tree; answer any two, 5 marks each

Topics covered

• Boolean algebra
• Principle of duality
• Propositional logic
• Karnaugh maps
• Combinational circuits
• Algorithm complexity
• Recursion in Java
• Arrays
• Inheritance and abstract classes
• Queues
• Linked lists
• Binary trees

Questions from this paper

1. Convert the infix expression (P + Q / R) * (S + T / U) / V to prefix form.
2. An array Arr[3.....8, −5.....5] is stored in row-major order. The address of Arr[5][−2] is 5120 and each element occupies 4 bytes. Find the base address of the array.
3. If x implies y, where x is “You stay calm” and y is “You will succeed”, write the converse.
4. Write the reduced expression of F(A, B, C) = Σ(0, 1, 2, 3, 4, 5, 6, 7).
5. Reduce F(A, B, C, D) = Σ(0, 1, 2, 4, 8, 9, 10, 12) with a 4-variable Karnaugh map, showing the groups.
6. Customer requests are stored and removed in the order they are received. Name this data structure and state the principle it follows.