Question 1

In a many-to-many binary relationship an occurrence of one entity type can be associated with many occurrences of another entity type while each occurrence of the second entity type can be associated with only one occurrence of the first.

Accepted Answer

In a many-to-many binary relationship, an occurrence of one entity type can be associated with many occurrences of another entity type, and vice versa; each occurrence of the second entity type can also be associated with many occurrences of the first entity type.

Question 2

Intersection data describes the many-to-many relationship between two entities.

Accepted Answer

Intersection data represents the relationship where multiple instances of one entity may relate to multiple instances of another entity, hence it is a many-to-many relationship.

Question 3

In a one-to-many binary relationship an occurrence of one entity type can be associated with many occurrences of the same entity type.

Accepted Answer

In a one-to-many binary relationship, an occurrence of one entity type is associated with many occurrences of another entity type, not the same entity type.

Question 4

A one-to-one binary relationship involves a single entity type.

Accepted Answer

A one-to-one binary relationship involves two different entity types where an instance of one entity type relates to exactly one instance of the other entity type.

Question 5

The modality of a relationship is the minimum number of entity occurrences that can be involved in a relationship.

Accepted Answer

The definition of modality in a relationship refers to the minimum number of times an entity can participate in a relationship. It can be either 1 (mandatory) or 0 (optional).

Question 6

In a university setting, each student is paired with another student for the purpose of getting assignments and turning in work for the other if he is out of school for any reason. This is a _____ relationship.
A) one-to-one binary
B) one-to-many binary
C) many-to-many binary
D) one-to-one unary
E) one-to-many unary

Accepted Answer

This is a one-to-one relationship because each student is paired with only one other student for the purpose of sharing assignments and work. It is a unary relationship because each student is only connected to one other student in the pairing.

Question 7

In a one-to-many binary relationship an occurrence of one entity type can be associated with many occurrences of another entity type while each occurrence of the second entity can be associated with only one occurrence of the first.

Accepted Answer

This is the definition of a one-to-many binary relationship.

Question 8

A ternary relationship allows an occurrence of one entity type to be associated with _____.
A) a single occurrence of the same entity type
B) multiple occurrences of the same entity type
C) a single occurrence of only one other entity type
D) multiple occurrences of only one other entity type
E) multiple occurrences of two other entity types

Accepted Answer

A ternary relationship allows an occurrence of one entity type to be associated with multiple occurrences of two other entity types.

Question 9

In a many-to-many binary relationship an occurrence of one entity type can be associated with many occurrences of another entity type while each occurrence of the second entity type can be associated with many occurrences of the first.

Accepted Answer

In a many-to-many binary relationship, both entities can be associated with multiple occurrences of each other. This is the definition of a many-to-many relationship. Therefore, the statement is true.

Question 10

A binary relationship is a relationship between two entity types.

Accepted Answer

A binary relationship is a relationship between two entity types, such as a "customer places an order" or a "student enrolls in a course".

Question 11

The cardinality of a relationship is the maximum number of entity types that can be involved in it.

Accepted Answer

The cardinality of a relationship refers to the maximum number of occurrences of one entity type for a single occurrence of the related entity type, not the maximum number of entity types that can be involved in it. This is known as the arity of the relationship.

Question 12

The Entity-Relationship (E-R) model is designed to diagram entity types and the relationships between them.

Accepted Answer

The Entity-Relationship (E-R) model is indeed designed to diagram entity types and the relationships between them.

Question 13

In a one-to-many binary relationship an occurrence of one entity type can be associated with many occurrences of another entity type.

Accepted Answer

In a one-to-many binary relationship, one occurrence of an entity can be associated with many occurrences of another entity, but each occurrence of the second entity can only be associated with one occurrence of the first entity.

Question 14

A university wants to keep track of which professor taught which subject to which student. This is a _____ relationship.
A) one-to-many unary
B) many-to-many unary
C) one-to-many binary
D) many-to-many binary
E) ternary

Accepted Answer

The answer of A university wants to keep track of...

Question 15

In a university setting, every professor reports to another professor who is the department chair. This is a _____ relationship.
A) one-to-one binary
B) one-to-many binary
C) many-to-many binary
D) one-to-one unary
E) one-to-many unary

Accepted Answer

In this scenario, each professor reports to a single department chair, but a department chair can oversee multiple professors. This establishes a one-to-many relationship. The term "unary" is used because the relationship is within the same entity group (professors to professors).

Question 16

A binary relationship is one in which each entity occurrence is associated with exactly two other entity occurrences.

Accepted Answer

A binary relationship is one in which there are two entities involved, but it does not specify that each entity occurrence must be associated with exactly two other entity occurrences. It simply means the relationship involves two distinct entities.

Question 17

The cardinality of a relationship is the maximum number of entity occurrences that can be involved in it.

Accepted Answer

The statement accurately defines cardinality.

Question 18

The Entity-Relationship (E-R) model is designed to diagram entity types that are independent of each other.

Accepted Answer

The Entity-Relationship (E-R) model is designed to diagram not only entity types but also the relationships between them, indicating how entities interact with each other.

Question 19

A dependent entity _____.
A) is the same as an associative entity
B) can only exist as part of a many-to-many binary relationship
C) can only be present if the entity it depends on is present
D) requires intersection data if it is part of a many-to-many binary relationship
E) requires intersection data if it is part of a ternary relationship

Accepted Answer

A dependent entity is an entity that cannot exist without the presence of another entity, which it depends on. Therefore, it can only be present if the entity it depends on is present. Choice A is incorrect because an associative entity is a type of entity used in many-to-many binary relationships, but not all dependent entities are associative. Choice B is incorrect because a dependent entity can also exist as part of a one-to-many or one-to-one relationship. Choices D and E are incorrect because intersection data is only required for many-to-many binary relationships or ternary relationships, respectively.

Question 20

A one-to-one binary relationship associates one occurrence of an entity type with one occurrence of another entity type.

Accepted Answer

A one-to-one binary relationship defines a unique relationship between one occurrence of an entity type and one occurrence of another entity type. There is no possibility of having more or less than one occurrence on either side of the relationship.

Quiz 2: Data Modeling