Relational Database

This is the correct answer. There are five types of attributes in database. These are :-1.) Simple attribute 2.) Composite attribute 3.) Single-valued attribute 4.) Multivalued attribute 5.) Derived attributeThere is no attribute named unary. Unary is a type of relation which is known as degree of relation(unary, binary, ternary etc.). So this is the correct answer according to the question.

This is the correct answer. Connectivity means how many instances of one entity are associated with how many instances of other entity.The connectivity of a relationship can be classified in 4 types. These are :-1.) One to one (1 : 1)2.) One to many (1 : M)3.) Many to one (M : 1)4.) Many to many(M : N)So this answer is also correct.

This is the correct answer. The entity set that doesn’t have sufficient attributes to form a primary key and relies on another for its identification is called a weak entity set. It doesn’t have a primary key.So this is correct answer.

As I explained the reason both options 1 & 3 are correct.So this is the correct choice.

This is the correct answer. There is no particular reason to explain this answer, because there is a name convention in DBMS. The members of weak entity set are called subordinate entity set.So this is the correct answer.

This is correct answer. There are 3 types of record based data models. These are :-1.) Hierarchical model2.) Network model3.) Relational modelThese are the 3 models.So this is the correct choice.

This is true choice. Q statement is correct because the primary key and the foreign key can exist in the same relation. Moreover foreign key can refer to the primary key in the same relation.So this is correct choice.

This is correct choice. Statement R is true because we can apply restrictions on values of attributes these are known as constraints.So this answer is correct.

There are five types of attributes in database. These are :-1.) Simple attribute2.) Composite attribute 3.) Single-valued attribute4.) Multivalued attribute5.) Derived attribute So this is the correct answer .

This is the incorrect answer. there are 3 types of data models present in DBMS. These are :-1.) Object based data model2.) Record based data model3.) Physical data modelSo this is the incorrect answer.

As I explained both 2 & 3 options are correct. So this is correct choice.

This is the correct answer. There are seven types of keys in relational database. These are :-1.) Primary key2.) Candidate key3.) Super key4.) Foreign key5.) Alternate key6.) Artificial key7.) Composite keySo this is the correct answer.

Option P is correct because a candidate key is a key that uniquely identifies a row in a relation. So this cannot be null as it uniquely identifies a row.Option R is correct because primary key is chosen from a set of candidate keys. In other words all the candidate keys are the candidates for the primary key. So in this way all the candidate keys are primary keys.So this is the correct answer.Option Q is false because If the primary key is composed of more than one attribute then these attributes are known as prime attributes not super attributes.

As I explained that all of the given options are true. So this is correct choice.

This is the correct answer. There is no particular reason to explain this answer, because there is a name convention in DBMS. The members of strong entity set are called dominant entity set.So this is the correct answer.