Meerut Institute of Technology (PC), Meerut
First Sessional Examination 2021-22
Name of the course: BCA
Name of the subject: Introduction to DBMS subject code: BCA 501
Time Allowed: 11/2 Hours Maximum Marks: 25
Section – A (1x5 = 5) (Answer in 25-50 words)
(This section contains 5 questions, each carrying one mark. Answer should be brief)
Q1. What is DBMS?(co-1)
Ans. The database is a collection of inter-related data which is used to retrieve, insert and delete the data
efficiently. It is also used to organize the data in the form of a table, schema, views, and reports, etc.
For example: The college Database organizes the data about the admin, staff, students and faculty etc.
Q2. Define Entity?(co-1)
Ans. Entity in DBMS can be a real-world object with an existence, For example, in a College database, the
entities can be Professor, Students, Courses, etc.
Entities has attributes, which can be considered as properties describing it, for example, for Professor entity,
the attributes are Professor_Name, Professor_Address, Professor_Salary, etc.
Q3. What do you mean by Primary Key?(co-1)
Ans. It is the first key which is used to identify one and only one instance of an entity uniquely. An entity
can contain multiple keys as we saw in PERSON table. The key which is most suitable from those lists
become a primary key.For example: In the EMPLOYEE table, ID can be primary key since it is unique for
each employee.
Q4.What is Data?(co-1)
Ans. Data, in the context of databases, refers to all the single items that are stored in a database, either
individually or as a set. Data in a database is primarily stored in database tables, which are organized into
columns that dictate the data types stored therein. So, if the “Customers” table has a column titled
“Telephone Number,” whose data type is defined as “Number,” then only numerals can be stored in that
column.
Q5. What do you mean by one to many relationships?(co-1)
Ans One to Many Relationship: Any single rows of the first table can be related to one or more rows of
the second tables, but the rows of second tables can only relate to the only row in the first table. It is also
known as a many to one relationship.
, Section – B (2.5x2 = 5) (Answer in 100-150 words)
(This section contains 3 questions, you are required to attempt any 2 questions each carrying 2.5
marks)
Q1.What do you mean by Data Models?(co-2)
Data Model is the modeling of the data description, data semantics, and consistency constraints of
the data. It provides the conceptual tools for describing the design of a database at each level of data
abstraction. Therefore, there are following three data models used for understanding the structure of
the database:
Relational Model
The relational data model is the most famous data model and is used by the majority around the world.This
is a simple but efficient data model and has the capability to handle data in the best possible manner.
Tables are used to handle the data in the relational data model. An example of a table containing data
about the Employees in a company is as follows −
<Employee>
Emp_Number Emp_Name Emp_Designation Emp_Age Emp_Salary
1 Jack Manager 35 50000
2 Tom Technician 25 25000
3 Henry Secretary 50 30000
Hierarchical Model
A hierarchical database model is a data model in which the data are organized into a tree-like structure.
The data are stored as records which are connected to one another through links. A record is a collection
of fields, with each field containing only one value. The type of a record defines which fields the record
contains.
First Sessional Examination 2021-22
Name of the course: BCA
Name of the subject: Introduction to DBMS subject code: BCA 501
Time Allowed: 11/2 Hours Maximum Marks: 25
Section – A (1x5 = 5) (Answer in 25-50 words)
(This section contains 5 questions, each carrying one mark. Answer should be brief)
Q1. What is DBMS?(co-1)
Ans. The database is a collection of inter-related data which is used to retrieve, insert and delete the data
efficiently. It is also used to organize the data in the form of a table, schema, views, and reports, etc.
For example: The college Database organizes the data about the admin, staff, students and faculty etc.
Q2. Define Entity?(co-1)
Ans. Entity in DBMS can be a real-world object with an existence, For example, in a College database, the
entities can be Professor, Students, Courses, etc.
Entities has attributes, which can be considered as properties describing it, for example, for Professor entity,
the attributes are Professor_Name, Professor_Address, Professor_Salary, etc.
Q3. What do you mean by Primary Key?(co-1)
Ans. It is the first key which is used to identify one and only one instance of an entity uniquely. An entity
can contain multiple keys as we saw in PERSON table. The key which is most suitable from those lists
become a primary key.For example: In the EMPLOYEE table, ID can be primary key since it is unique for
each employee.
Q4.What is Data?(co-1)
Ans. Data, in the context of databases, refers to all the single items that are stored in a database, either
individually or as a set. Data in a database is primarily stored in database tables, which are organized into
columns that dictate the data types stored therein. So, if the “Customers” table has a column titled
“Telephone Number,” whose data type is defined as “Number,” then only numerals can be stored in that
column.
Q5. What do you mean by one to many relationships?(co-1)
Ans One to Many Relationship: Any single rows of the first table can be related to one or more rows of
the second tables, but the rows of second tables can only relate to the only row in the first table. It is also
known as a many to one relationship.
, Section – B (2.5x2 = 5) (Answer in 100-150 words)
(This section contains 3 questions, you are required to attempt any 2 questions each carrying 2.5
marks)
Q1.What do you mean by Data Models?(co-2)
Data Model is the modeling of the data description, data semantics, and consistency constraints of
the data. It provides the conceptual tools for describing the design of a database at each level of data
abstraction. Therefore, there are following three data models used for understanding the structure of
the database:
Relational Model
The relational data model is the most famous data model and is used by the majority around the world.This
is a simple but efficient data model and has the capability to handle data in the best possible manner.
Tables are used to handle the data in the relational data model. An example of a table containing data
about the Employees in a company is as follows −
<Employee>
Emp_Number Emp_Name Emp_Designation Emp_Age Emp_Salary
1 Jack Manager 35 50000
2 Tom Technician 25 25000
3 Henry Secretary 50 30000
Hierarchical Model
A hierarchical database model is a data model in which the data are organized into a tree-like structure.
The data are stored as records which are connected to one another through links. A record is a collection
of fields, with each field containing only one value. The type of a record defines which fields the record
contains.
