Rapid Fire Quiz in ER Model

Welcome to the rapid fire quiz on the ER model. You will have 20 seconds to answer each question.

Question 1

Situation

• Instance Provided: Students relation table.
• Objective: For student name and student age to be a key, the value should not be equal to ___.

Key Points

• Student name alone cannot be a key as there are duplicate entries.
• The unique combination of student name and age must be established.
• Answer: 19

Question 2

Situation

• Objective: Identify the incorrect statement about the basic ER and relational models.

Options

• A: An attribute of an entity can have more than one value.
• B: An attribute of an entity can be composite.
• C: In a row of a relational table, an attribute can have more than one value.
• D: In a row of a relational table, an attribute can have exactly one value or a null value.

Key Points

• Option C is incorrect; an attribute in a relational table should not have more than one value due to issues of inconsistency and redundancy.
• Answer: Option C

Question 3

Situation

• Objective: Identify the symbol used for supporting many to one relationship of a weak entity set in an ER diagram.

Options

• A: Rectangles with double or bold border.
• B: Diamonds with double or bold border.
• C: Ovals containing underlined identifier.
• D: Ovals with double or bold border.

Key Points

• Relationships in ER diagrams are represented by diamonds, with weak entity sets shown by double or bold-bordered diamonds.
• Answer: Option B

Question 4

Situation

• Objective: Determine the correct behavior between dominant entity Y and subordinate entity X.

Options

• A: If X is deleted, then Y is also deleted.
• B: If Y is deleted, then X is also deleted.
• C: If Y is deleted, then X is not deleted.
• D: None of the above.

Key Points

• X depends on Y. If Y is deleted, X must also be deleted.
• Answer: Option B

Question 5

Situation

• Objective: Under which condition can the relational table for R be merged with that of A?
• Conditions: R is a relationship between entity types A and B, lacking its own attributes.

Options

• A: R is one to many, and A’s participation in R is total.
• B: R is one to many, and A’s participation in R is partial.
• C: R is many to one, and A’s participation in R is total.
• D: R is many to one, and A’s participation in R is partial.

Key Points

• Merging is possible when participation is total and R is many to one with A.
• Answer: Option C

Please share your scores in the comments section. Hope you found this session informative. Thank you for participating!