# ER Model

 Question 1
Which one of the following is used to represent the supporting many-one relationships of a weak entity set in an entity-relationship diagram?
 A Diamonds with double/bold border B Rectangles with double/bold border C Ovals with double/bold border D Ovals that contain underlined identifiers
GATE CSE 2020   Database Management System
Question 1 Explanation:
 Question 2
In E-R model, Y is the dominant entity and X is subordinate entity
 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
ISRO CSE 2018   Database Management System
Question 2 Explanation:

 Question 3
In an Entity-Relationship (ER) model, suppose R is a many-to-one relationship from entity set E1 to entity set E2. Assume that E1 and E2 participate totally in R and that the cardinality of E1 is greater than the cardinality of E2.
Which one of the following is true about R?
 A Every entity in E1 is associated with exactly one entity in E2. B Some entity in E1 is associated with more than one entity in E2. C Every entity in E2 is associated with exactly one entity in E1. D Every entity in E2 is associated with at most one entity in E1.
GATE CSE 2018   Database Management System
Question 3 Explanation:
 Question 4
Which symbol denote derived attributes in ER Model?
 A Double ellipse B Dashed ellipse C Squared ellipse D Ellipse with attribute name underlined
ISRO CSE 2017   Database Management System
Question 4 Explanation:
 Question 5
An ER model of a database consists of entity types A and B. These are connected by a relationship R which does not have its own attribute. Under which one of the following conditions, can the relational table for R be merged with that of A?
 A Relationship R is one-to-many and the participation of A in R is total B Relationship R is one-to-many and the participation of A in R is partial C Relationship R is many-to one and the participation of A in R is total D Relationship R is many-to one and the participation of A in R is partial
GATE CSE 2017 SET-2   Database Management System
Question 5 Explanation:

There are 5 questions to complete.