GATE Questions & Answers of ER-model

What is the Weightage of ER-model in GATE Exam?

Total 7 Questions have been asked from ER-model topic of Databases subject in previous GATE papers. Average marks 1.43.

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?

An ER model of a database consists of entity types A and B. These are connected by a relationship R which dose not have its own attribute. Under which one of the following condiditons, can the relational table for R be merged with that of A?

Consider an Entity-Relationship(ER) model in which entity sets E1 and E2 are connected by an m:n relationship R12. E1 and E3 are connected by a 1: (1 on the side of E1 and n on the side of E3) relationship R13.

E1 has two single-valued attributes a11 and a12 of which a11 is the key attribute. E2 has two single-valued attributes a21 and a22 of which is a21 the key attribute. E3 has two single-valued attributes a31 and a32 of which a31 is the key attribute. The relationships do not have any attributes.

If a relational model is the derived from the above ER model, then the minimum number of relations that would be generated if all the relations are in 3NF is _______.

Given an instance of the STUDENTS relation as shown below:

StudentID        StudentName        StudentEmail         StudentAge          CPI       
2345    Shankar      shankar@math X 9.4
1287    swati      swati@ee 19 9.5
7853    shankar      shankar@cse 19 9.4
9876    swati      swati@mech 18 9.3
8765    ganesh    ganesh@civil 19 8.7

For (StudentName,StudentAge) to be a key for this instance,the value X should NOT be equal to ________.

Given the basic ER and relational models, which of the following is INCORRECT?

Consider the following ER diagram

The minimum number of tables needed to represent M, N, P, R1, R2 is

Consider the following ER diagram

Which of the following is a correct attribute set for one of the tables for the correct answer to the above question?