DR. BABASAHEB AMBEDKAR TECHNOLOGICAL UNIVERSITY, LONERE

Mid-Semester Examination – 2025

Subject: Database Management Systems (DBMS) | Semester: IV | Max Marks: 20 | Duration: 1 Hr
Course: B.Tech
Branch: Information Technology
Units Covered: I & II
Date: 30/08/2025

Q.1 Multiple Choice Questions (6 × 1 = 6 Marks)

  1. Which of the following is not an advantage of DBMS?
    1. Data redundancy control
    2. Improved data security
    3. High maintenance cost
    4. Data consistency
  2. Data abstraction in DBMS is mainly used to:
    1. Hide irrelevant details
    2. Improve query speed
    3. Remove duplicate records
    4. Store backup copies
  3. In E-R diagrams, a diamond represents:
    1. Entity
    2. Attribute
    3. Relationship
    4. Primary Key
  4. Which of the following is a valid relational algebra operation?
    1. Join
    2. Sum
    3. Multiply
    4. Loop
  5. Which SQL command is used to remove a table?
    1. DELETE
    2. DROP
    3. REMOVE
    4. ERASE
  6. A foreign key is used to:
    1. Ensure data security
    2. Maintain referential integrity
    3. Speed up queries
    4. Remove redundancy

Q.2 Answer the following (2 × 3 = 6 Marks)

  1. Explain logical data independence with an example. (3)
  2. Differentiate between strong entity and weak entity with suitable examples. (3)

Q.3 Answer the following (2 × 4 = 8 Marks)

  1. Draw and explain a sample E-R diagram for a university database with students, courses, and enrollments. (4)
  2. Explain integrity and referential constraints in the relational model with suitable SQL examples. (4)