Detailed Guide & Information
IOCL Recruitment 2026 CBT Exam Analysis — CS/IT Memory-Based Questions
Computer Based Test (CBT) held on 24 September 2026 for Graduate Engineers (CS/IT). Attempt verified memory questions with official solutions and instant scoring.
About IOCL Recruitment 2026 & CBT Structure
Indian Oil Corporation Limited (IndianOil) conducted this CBT under Advertisement No. IOCL/CO-HR/RECTT/2026/01 (dated 14 August 2026) for Graduate Engineers (Grade A) across CS/IT, Chemical, Mechanical, Civil, and Electrical streams. Full details are published in the Official Advertisement PDF.
1. Important Recruitment Dates
| Recruitment Event | Important Dates |
|---|---|
| Online Registration Window | 14 August 2026 to 03 September 2026 |
| Admit Card Download | 15 September 2026 onwards |
| Computer Based Test (CBT) Date | 24 September 2026 |
| Interview & GD Rounds | October – November 2026 (Tentative) |
2. CBT Exam Pattern & Marking Scheme
The CBT comprises 100 objective MCQs across two sections with +1.00 Mark for correct answers and −0.25 Mark negative marking for incorrect attempts:
| Section | Curriculum & Areas | Questions | Duration |
|---|---|---|---|
| Section A: General Aptitude | Quantitative Aptitude (20), Logical Reasoning (15), Verbal English (15) | 50 Questions | 60 Minutes |
| Section B: Domain Knowledge | CS/IT Core Engineering Subjects | 50 Questions | 90 Minutes |
Weightage for final merit selection: CBT = 85%, Group Discussion / Group Task = 5%, Personal Interview = 10%.
A Binary Search Tree (BST) has 20 nodes with exactly two children and 15 nodes with exactly one child. How many leaf nodes does this tree contain?
In any binary tree, the relationship between the number of leaf nodes (N0) and the number of nodes with two children (N2) is given by:
The single-child nodes (N1 = 15) do not alter this relationship. Therefore, Option C (21) is correct.
Four processes P1–P4 have arrival & burst times: P1(0,8), P2(1,2), P3(2,9), P4(3,5). Using Preemptive Shortest Remaining Time First (SRTF), what is the average waiting time?
| Process | Arrival Time | Burst Time |
|---|---|---|
| P1 | 0 | 8 |
| P2 | 1 | 2 |
| P3 | 2 | 9 |
| P4 | 3 | 5 |
Timeline: P1 runs 0→1. P2 preempts P1 and completes 1→3. P4 executes 3→8. P1 resumes 8→15. P3 executes 15→24.
In a table, column A contains five values: [1, 3, NULL, NULL, 4]. What do COUNT(*), COUNT(A), SUM(A), and AVG(A) evaluate to, respectively?
• COUNT(*) counts all rows = 5.
• COUNT(A) ignores NULL values = 3.
• SUM(A) = 1 + 3 + 4 = 8.
• AVG(A) = 8 / 3 ≈ 2.67.
COUNT(*), all SQL aggregates ignore NULL values.
Official Quick Answer Key
| Q. No. | Subject Topic | Correct Option | Marking |
|---|---|---|---|
| 01 | Binary Search Trees (Leaves Relation) | Option C (21) | +1.00 / −0.25 |
| 02 | Operating Systems (SRTF Wait Time) | Option B (5.0) | +1.00 / −0.25 |
| 03 | DBMS (SQL NULLs & Aggregates) | Option B (5, 3, 8, 2.67) | +1.00 / −0.25 |
📝 IOCL Exam 2026: Share Recalled Questions
24th September Exam Memory-Based Question Collection. Write whatever questions and options you remember from the exam! You can submit for all sections and subjects.