✅ WBJEE JECA Computer Applications – Mock Test 4
🟩 C Programming
1. What is the result of 5 % 2 in C?
a. 0
b. 2
c. 1
d. 5
Answer: c
2. Which of the following is not a valid data type in C?
a. float
b. real
c. char
d. int
Answer: b
3. Which header file is required for printf()?
a. stdio.h
b. stdlib.h
c. math.h
d. conio.h
Answer: a
4. What is the output of:
int a = 5;
printf("%d", a++);
a. 6
b. 5
c. Error
d. Undefined
Answer: b
5. Which keyword is used to prevent modification of a variable?
a. static
b. const
c. volatile
d. signed
Answer: b
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🟨 Object Oriented Programming
6. In C++, polymorphism allows:
a. One function many forms
b. Many classes one function
c. One class only
d. None
Answer: a
7. Which concept binds data and functions together?
a. Polymorphism
b. Encapsulation
c. Inheritance
d. Abstraction
Answer: b
8. Which feature allows reusing code?
a. Encapsulation
b. Inheritance
c. Abstraction
d. Object
Answer: b
9. What is a destructor in C++?
a. Constructor
b. Overloaded function
c. Function to destroy object
d. Static function
Answer: c
10. friend functions can access:
a. Only public
b. Only private
c. Private & protected members
d. Static only
Answer: c
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🟧 UNIX
11. Which command shows calendar?
a. date
b. time
c. cal
d. clock
Answer: c
12. Command to create empty file:
a. make
b. touch
c. open
d. newfile
Answer: b
13. Which of the following is a file permission command?
a. chmod
b. grep
c. cut
d. ps
Answer: a
14. To list files in long format:
a. ls -l
b. list -a
c. show -all
d. dir -f
Answer: a
15. kill command is used to:
a. Pause a process
b. Start a process
c. Terminate a process
d. Run a command
Answer: c
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🟩 Data Structures
16. What is the time complexity of linear search?
a. O(log n)
b. O(n)
c. O(1)
d. O(n^2)
Answer: b
17. Which data structure uses FIFO?
a. Stack
b. Array
c. Queue
d. Tree
Answer: c
18. Which data structure is used for recursion?
a. Queue
b. Stack
c. Array
d. List
Answer: b
19. Which tree traversal visits root first?
a. Inorder
b. Preorder
c. Postorder
d. Level order
Answer: b
20. What is the height of a tree with only root node?
a. 0
b. 1
c. 2
d. -1
Answer: a
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🟦 Operating System
21. Which of these is not a type of scheduler?
a. Short-term
b. Long-term
c. Mid-term
d. Time-term
Answer: d
22. Which is a non-preemptive scheduling algorithm?
a. Round Robin
b. SJF (non-preemptive)
c. Priority (preemptive)
d. Multilevel
Answer: b
23. In paging, each page is:
a. Fixed size
b. Variable size
c. Infinite
d. Virtual
Answer: a
24. Process control block (PCB) contains:
a. Process state
b. Program counter
c. Memory limits
d. All
Answer: d
25. Thrashing occurs when:
a. Too many processes are in memory
b. I/O stops
c. CPU fails
d. Paging is optimized
Answer: a
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🟥 Database Management System
26. Which is not a valid SQL clause?
a. WHERE
b. SELECT
c. WHAT
d. GROUP BY
Answer: c
27. Which command is used to update data in SQL?
a. UPDATE
b. MODIFY
c. CHANGE
d. SET
Answer: a
28. A relation in a DBMS is a:
a. Table
b. Record
c. Field
d. Row
Answer: a
29. Normalization helps in:
a. Reducing redundancy
b. Increasing size
c. Increasing complexity
d. Slowing queries
Answer: a
30. NOT NULL constraint means:
a. Unique only
b. No NULL value allowed
c. Duplicate allowed
d. Both NULL and empty
Answer: b
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🟫 Computer Networks
31. Which layer ensures error-free delivery?
a. Transport
b. Network
c. Data Link
d. Session
Answer: c
32. MAC address is:
a. Logical address
b. IP address
c. Physical address
d. None
Answer: c
33. Protocol for secure web:
a. HTTP
b. FTP
c. HTTPS
d. TCP
Answer: c
34. Which topology uses token passing?
a. Star
b. Ring
c. Mesh
d. Bus
Answer: b
35. DNS translates:
a. IP to MAC
b. MAC to IP
c. Domain to IP
d. IP to hostname
Answer: c
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🟪 Software Engineering
36. Prototyping model is useful for:
a. Rigid requirement
b. Clear design
c. User feedback
d. Final delivery
Answer: c
37. SRS contains:
a. Hardware design
b. Software code
c. Functional + Non-functional requirements
d. Binary codes
Answer: c
38. Testing each module separately is called:
a. Unit testing
b. Integration testing
c. System testing
d. Beta testing
Answer: a
39. IEEE stands for:
a. Indian Engineering
b. International Electrical Engineers
c. Institute of Electrical and Electronics Engineers
d. None
Answer: c
40. Which is not a software metric?
a. LOC
b. Cyclomatic Complexity
c. RAM
d. Defect density
Answer: c
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🧠 Machine Learning
41. Which algorithm is supervised?
a. K-means
b. Decision Tree
c. DBSCAN
d. Apriori
Answer: b
42. Which algorithm is for classification?
a. Linear Regression
b. Decision Tree
c. K-means
d. PCA
Answer: b
43. Overfitting occurs when model:
a. Performs poorly on training
b. Fits training data too well
c. Has no learning
d. Is under-trained
Answer: b
44. Which one is unsupervised?
a. SVM
b. Random Forest
c. K-means
d. Logistic Regression
Answer: c
45. ANN is used for:
a. Sorting
b. Regression and classification
c. File management
d. Encryption
Answer: b
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🧩 Mixed Concepts
46. C is a:
a. OOP language
b. High level language
c. Assembly language
d. DBMS
Answer: b
47. Full form of SQL:
a. Structured Query Language
b. Standard Question Language
c. Simple Quick Language
d. Server Query Language
Answer: a
48. Which file extension is used in UNIX script?
a. .exe
b. .bat
c. .sh
d. .run
Answer: c
49. LRU stands for:
a. Least Recently Updated
b. Less Read Unit
c. Least Recently Used
d. Low Resource Unit
Answer: c
50. Which algorithm is best for image classification?
a. DBMS
b. Naive Bayes
c. CNN
d. BFS
Answer: c
