Previous papers are the #1 preparation resource for O Level. NIELIT repeats concepts (not exact questions) from past exams. Solving 5+ years of papers gives you 80% exam readiness. Below are important questions from recent exams with answers. For the complete topic list, check our
detailed syllabus page.
Why Previous Papers Are So Important
NIELIT has a pattern — certain topics appear in every single exam. For M1: VLOOKUP, IP addressing, and network topologies are asked every time. For M3: list operations, file handling, and OOP basics repeat constantly. By solving 5 years of papers, you'll identify these patterns and know exactly what to focus on. Students who solve previous papers score 20-30% higher than those who only read textbooks. After practicing these, test yourself with our practice quiz (50 MCQs).
Q1What is the difference between RAM and ROM?
Answer: RAM (Random Access Memory) is volatile — data is lost when power is off. It's used for running programs. ROM (Read Only Memory) is non-volatile — data persists. It stores BIOS/firmware.
Q2Explain VLOOKUP function in Excel with syntax.
Answer: VLOOKUP searches for a value in the first column of a table and returns a value from another column. Syntax: =VLOOKUP(lookup_value, table_array, col_index_num, [range_lookup]). Always use FALSE for exact match.
Q3What is the difference between LAN, MAN, and WAN?
Answer: LAN: Local Area Network (within a building, <1km). MAN: Metropolitan Area Network (within a city, <100km). WAN: Wide Area Network (across countries, unlimited distance). Internet is the largest WAN.
Q4What is an IP address? Explain IPv4 vs IPv6.
Answer: IP address is a unique identifier for devices on a network. IPv4: 32-bit (e.g., 192.168.1.1), supports 4.3 billion addresses. IPv6: 128-bit (e.g., 2001:0db8::1), supports virtually unlimited addresses.
Q5What is a firewall? Name its types.
Answer: A firewall monitors and controls network traffic based on security rules. Types: Packet filtering, Stateful inspection, Proxy firewall, Next-gen firewall (NGFW). It acts as a barrier between trusted and untrusted networks.
Q1What is the difference between a list and a tuple in Python?
Answer: List: mutable (can change), uses [], slightly slower. Tuple: immutable (cannot change), uses (), faster, can be used as dictionary keys. Use lists for collections that change, tuples for fixed data.
Q2Write a Python program to check if a number is prime.
Answer: def is_prime(n):\n if n < 2: return False\n for i in range(2, int(n**0.5)+1):\n if n % i == 0: return False\n return True\n\nKey: Only check up to √n for efficiency.
Q3Explain the difference between append() and extend() in Python.
Answer: append(x) adds x as a single element (even if x is a list). extend(iterable) adds each element individually. Example: [1,2].append([3,4]) → [1,2,[3,4]]. [1,2].extend([3,4]) → [1,2,3,4].
Q4What is exception handling? Explain try-except with example.
Answer: Exception handling prevents program crashes. try: risky code. except ErrorType: handle it. finally: always runs.\n\ntry:\n result = 10/0\nexcept ZeroDivisionError:\n print("Cannot divide by zero")\nfinally:\n print("Done")
Q5What is inheritance in Python? Give an example.
Answer: Inheritance lets a child class reuse code from parent class. class Animal: def speak(self): pass. class Dog(Animal): def speak(self): return "Woof". Dog inherits all Animal methods and can override them.