Interview Questions for Freshers: Top 100 with Answers 2026
Top 100 technical and HR interview questions for freshers in 2026. Java, Python, OOPs, DBMS, OS, data structures — with concise answers for BCA, B.Tech, MCA.
This is the most comprehensive list of technical + HR interview questions for freshers appearing at TCS, Infosys, Wipro, Accenture, Capgemini, and similar companies in 2026.
Section 1: Java / OOPs (Most Common)
Q1: What are the four pillars of OOP?
Encapsulation, Inheritance, Polymorphism, Abstraction.
Q2: What is the difference between overloading and overriding?
Overloading = same method name, different parameters (compile-time). Overriding = subclass redefines parent method (runtime).
Q3: What is the difference between abstract class and interface?
Abstract class can have method bodies + fields; interface (Java 8+) can have default methods but is primarily contracts. A class can implement multiple interfaces but extend only one abstract class.
Q4: What is the difference between ArrayList and LinkedList?
ArrayList: fast random access (O(1)), slow insert/delete in middle (O(n)). LinkedList: slow random access (O(n)), fast insert/delete at known position (O(1)).
Q5: Explain final, finally, and finalize.final = variable/method/class cannot be changed/overridden/inherited. finally = always-executed block in try-catch. finalize() = called by GC before object destruction (deprecated in Java 9).
Q6: What is multithreading? What are Thread states?
Multithreading = concurrent execution. States: New → Runnable → Running → Blocked/Waiting → Terminated.
Q7: What is the difference between String, StringBuilder, and StringBuffer?
String: immutable. StringBuilder: mutable, not thread-safe. StringBuffer: mutable, thread-safe (synchronized).
Q8: What are the access modifiers in Java?private (class only), default (package), protected (package + subclass), public (everywhere).
Q9: What is a constructor? Can a constructor be private?
Constructor initializes an object. Yes, private constructor is used in Singleton pattern.
Q10: What is the difference between == and .equals() in Java?== compares references. .equals() compares values (if overridden properly).
Section 2: Python
Q11: What is a list comprehension?[x*2 for x in range(10) if x % 2 == 0] — concise syntax to create lists.
Q12: Difference between list and tuple?
List is mutable; tuple is immutable and faster.
Q13: What are decorators in Python?
Functions that modify other functions without changing their code. Used with @decorator syntax.
Q14: What is a lambda function?
Anonymous function: square = lambda x: x**2
Q15: Difference between is and ==?is checks identity (same object in memory); == checks equality of values.
Section 3: DBMS / SQL
Q16: What are ACID properties?
Atomicity (all or nothing), Consistency (data remains valid), Isolation (transactions don't interfere), Durability (committed data persists).
Q17: Write a query to find the second highest salary.
SELECT MAX(salary) FROM employees WHERE salary < (SELECT MAX(salary) FROM employees);
Q18: What is normalization? Explain 1NF, 2NF, 3NF.
1NF: atomic values, no repeating groups. 2NF: 1NF + no partial dependency. 3NF: 2NF + no transitive dependency.
Q19: Difference between DELETE, TRUNCATE, DROP.
DELETE: removes rows (can rollback, can use WHERE). TRUNCATE: removes all rows (fast, no rollback). DROP: removes entire table/structure.
Q20: What is an index? When would you not use one?
Index speeds up reads. Avoid on small tables, frequently updated columns, or columns with low selectivity.
Section 4: Operating Systems
Q21: What is a process vs a thread?
Process: independent program with its own memory space. Thread: unit of execution within a process, shares memory.
Q22: What is deadlock? What are its conditions?
Deadlock = processes waiting for each other indefinitely. Conditions: Mutual exclusion, Hold and wait, No preemption, Circular wait.
Q23: What is virtual memory?
Technique that uses disk space to simulate additional RAM, allowing programs larger than physical memory to run.
Q24: What is paging vs segmentation?
Paging: fixed-size blocks (pages). Segmentation: variable-size logical segments. Paging causes internal fragmentation; segmentation causes external fragmentation.
Q25: What is a semaphore?
Synchronization primitive used to control access to shared resources. Binary semaphore = mutex.
Section 5: Computer Networks
Q26: OSI vs TCP/IP model?
OSI: 7 layers (Physical, Data Link, Network, Transport, Session, Presentation, Application). TCP/IP: 4 layers (Network Access, Internet, Transport, Application).
Q27: What is the difference between TCP and UDP?
TCP: reliable, connection-oriented, ordered delivery. UDP: unreliable, connectionless, faster.
Q28: What happens when you type a URL in a browser?
DNS lookup → TCP connection → HTTP request → Server processes → HTTP response → Browser renders.
Q29: What is HTTPS? How is it different from HTTP?
HTTPS = HTTP + TLS/SSL encryption. Data is encrypted in transit. Uses certificate authority for authentication.
Q30: What is a MAC address vs IP address?
MAC: hardware address (Layer 2, permanent). IP: logical address (Layer 3, can change).
Section 6: Data Structures
Q31–Q40: Key DS questions covering stacks, queues, linked lists, trees, graphs, hashing, sorting (merge sort, quick sort), recursion, time complexity, and binary search — all standard for TCS/Infosys/Wipro written tests.
(Full 100-question list available in Classroom Tech's placement preparation program)
Section 7: HR Questions (Top 10)
Q41: Tell me about yourself.
Structure: Name → Education → Key skills → One achievement → Why this company.
Q42: What are your strengths?
Pick 2–3 real strengths and back each with a brief example.
Q43: Where do you see yourself in 5 years?
Be honest: "Growing as a software engineer, taking on more responsibility, ideally in AI/ML."
Q44: Why do you want to join [Company]?
Research the company. Mention specific: products, values, tech stack, growth opportunities.
Q45: Do you have any questions for us?
Always ask 1–2 questions: "What does the first 90 days look like?" or "What technologies does the team primarily use?"
About Satyaki Das & Classroom Tech
Satyaki Das is the Founder of Classroom Tech and Co-Founder of XShare. He holds an MTech in Computer Engineering from Jadavpur University and an MCA from Techno Main, Salt Lake, Kolkata. A Java Full Stack Developer at TCS, GATE-qualified, and Codevita Rank 848, Satyaki has 11+ years of teaching experience mentoring BCA, B.Tech, MCA, and working professionals into roles at TCS, Wipro, Infosys, Accenture, EY, Deloitte, and Capgemini.
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Satyaki Das conducts live mock interview sessions covering all these categories. Book one at topmate.io/classroom/page/1KfI4BZ5jf.