1. In the Entity-Relationship Model, relationships can have attributes. A. True
B. False
2. Attributes are the smallest division of data in ER diagram.
A. True
B. False
3. Which level of abstraction is the ER model most concerned with?
A. External.
B. Conceptual.
C. Physical.
D. Internal.
4. Consider the following relationship involving two entities, students and classes:A student can take many classes. A class can be taken by many students. How many tables can be used to represent this relationship in a schema?
A. 1.
B. 2.
C. 3.
D. All of them.

1. A. True

2. A. True

3. B. Conceptual.

4. Three (3).

Explanation:

An Entity-Relationship Model is used in databases to describe the structure and relationship between data elements known as entities.

1. True: In the Entity-Relationship Model, relationships can have attributes.

2. True: Attributes are the smallest division of data in ER diagram.

3. Conceptual: the level of abstraction which the Entity-Relationship Model most concerned with.

4. Consider the following relationship involving two entities, students and classes: A student can take many classes. A class can be taken by many students. The number of tables which can be used to represent this relationship in a schema is 3 because we are having three (3) parameters which are simply the students and the two entities.

In database management, the term "schema" is used to denote a representation of data.

A database schema is a structure which is typically used to represent the logical design of the database and as such represents how data are stored or organized and the relationships existing in a database management system. There are two (2) main categories of a database schema; physical database schema and logical database schema.

only #2 represents an object at rest on a table.

in #1, there is no normal force due to the table; the object is accelerating downward.

in #3, the vertical forces are not balanced; the object is accelerating downward.

in #4, neither the vertical nor the horizontal forces are balanced. the object is accelerating upwards and to the right.