CUET CS Chapter-Database Concepts 

MCQ-Based Questions for CUET Computer Science Chapter-Database Concepts 

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Practice Questions for CUET Computer Science chapter-Database Concepts SET-1

Computer Science - MCQ on Database Concepts

Class XII

Q. 1. Data redundancy is

a. collection of relevant data

b. duplication of data

c. storage of data in a database

d. security of data

Answer:

b. duplication of data (E K/-)

Q. 2. Data inconsistency

a. may exist because of data redundancy

b. can be eliminated by data redundancy

c. helps maintain the database

d. is a requirement of a good database

Answer:

a. may exist because of data redundancy (E K/-)

Q. 3. Database abstraction is

a. the detailed database structure

b. a vague database structure

c. hiding of complicated details from the user

d. laid down by Mr. E.F.Codd

Answer:

c. hiding of complicated details from the user (E K/-)

Q. 4. The 3 levels of abstraction are

a. Internal, Physical and External

b. Internal, Conceptual and Logical

c. Internal, Conceptual and External

d. Internal, Conceptual and Physical

Answer:

c. Internal, Conceptual and External (E K/-)

Q. 5. Abstraction at the Physical level ,

a. provides views according to user’s requirements

b. describes how data are actually stored

c. describes the relationships among the data

d. is closest to the user

Answer:

b. describes how data are actually stored (D K/-)

Q. 6. Abstraction at the Conceptual level

a. provides views according to user’s requirements

b. describes how data are actually stored

c. describes the relationships among the data

d. is closest to the user

Answer:

c. describes the relationships among the data (D K/-)

Q.7. Abstraction at the External level,

a. provides views according to user’s requirements

b. describes how data are actually stored

c. describes the relationships among the data

d. is closest to the user

Answer:

a. provides views according to user’s requirements (D K/-)

Q. 8. Data independence

a. refers to storage of data separately from information

b. refers to updation of all tables independently

c. keeps the data accurate and consistent

d. allows changes in structure without affecting access of data

Answer:

d. allows changes in structure without affecting access of data (D K/-)

Q. 9. The 3 main data models are

a. Object-Oriented, Network and Hierarchical

b. Relational, Network and Hierarchical

c. Relational, Object-based and Hierarchical

d. Object-based, Relational and Network

Answer:

b. Relational, Network and Hierarchical (E K/-)

Q. 10. Rows in a relation are also called

a. tuple

b. column

c. relation

d. attribute

Answer:

a. tuple (E K/-)

Q. 11. A table is also called

a. tuple

b. column

c. relation

d. attribute

Answer:

c. relation (E K/-)

Q. 12. A column is called

a. tuple

b. column

c. relation

d. attribute

Answer:

d. attribute (E K/-)

Q. 13. Domain is

a. the set of values existing in a column

b. the set of names of the relations

c. the set of possible values in a column

d. the product of number of rows and columns

Answer:

c. the set of possible values in a column (E K/-)

Q. 14. Degree is

a. number of columns in a table

b. number of rows in a table

c. the product of number of rows and columns

d. the same for every table

Answer:

a. number of columns in a table (E K/-)

Q. 15. Cardinality is

a. number of columns in a table

b. number of rows in a table

c. an unknown quantity for a table

d. the same for every table

Answer:

b. number of rows in a table (E K/-)

Q. 16 Primary Key

a. is the first column of a relation

b. stores NULL for unknown values

c. can have only unique values

d. can hold only numeric values

Answer:

c. can have only unique values (E K/-)

Q. 17. Foreign Key

a. is a column of another relation in the database

b. verifies values against the Primary Key in another relation

c. can have only unique and non-null values

d. specifies the possible values a column can have

Answer:

b. verifies values against the Primary Key in another relation (D K/-)

Q. 18. Alternate Keys

a. are Candidate Keys that are not part of the Primary Key

b. are Candidate Keys that can be used as Foreign Keys

c. are Foreign Keys that can also be used as Primary Keys

d. are Candidate Keys, including Primary Key

Answer:

a. are Candidate Keys that are not part of the Primary Key (E K/-)

Q. 19. Candidate Keys

a. cannot be part of the Primary Key

b. are the Foreign Key and Primary Key attributes

c. uniquely identifies rows in a table

d. uniquely identifies columns in a table

Answer:

c. uniquely identifies rows in a table (D K/-)

Q. 20. The select operation

a. selects conditions to be satisfied

b. selects columns that satisfy a condition

c. selects rows that satisfy a condition

d. selects relation that satisfy a condition

Answer:

c. selects rows that satisfy a condition (D U/A)

Practice Questions for CUET Computer Science chapter-Database Concepts SET-2

Q. 21. The project operation

a. selects conditions to be satisfied

b. selects columns that satisfy a condition

c. selects rows that satisfy a condition

d. selects relation that satisfy a condition

Answer:

b. selects columns that satisfy a condition (D U/A)

Q. 22 The Cartesian product

a. is a product of two relations

b. has as many rows as the sum of the 2 relations

c. has as many columns as the larger table

d. has rows that are common in participating tables

Answer:

a. is a product of two relations (E U/A)

Q. 23. The Union operation

a. produces a relation with double the number of tuples

b. produces a relation with tuples existing in any one relation

c. produces a relation with tuples of both the relations

d. produces a relation with tuples common to both relations

Answer:

d. produces a relation with tuples of both the relations (E U/A)

Q. 24. Which of the following statements is true?

a. A relation can have only one Primary Key

b. Every Primary Key value must exist as a Foreign Key

c. A Primary Key can have NULL or unique values

d. A Primary Key can be an Alternate Key

Answer:

a. A relation can have only one Primary Key (D U/A)

Q. 25. Which of the following statements is false?

a. Relational Algebra involves operations on one or more relations

b. The select operation gives a horizontal subset of the relation.

c. The project operation gives a vertical subset of a relation.

d. For select operation to work, the relation must be select compatible.

Answer:

d. For select operation to work, the relation must be select compatible. (D U/A)

Q. 26. Select operation

a. is denoted by the Greek letter ‘Π’

b. is denoted by the Greek letter ‘S’

c. is denoted by the Greek letter ‘d’

d. is denoted by the Greek letter ‘s’

Answer:

d. is denoted by the Greek letter ‘s’ (E K/-)

Q. 27. The union operation will not work if -

a. The number of columns in the 2 tables is different

b. The domains of the corresponding columns are the same

c. The number of rows in the 2 tables is different

d. The number of rows in the 2 tables is the same

Answer:

a. The number of columns in the 2 tables is different (E K/-)

Q. 28. Which of the following statements on Cartesian product is false?

a. The Cartesian product of two relations r1 and r2 is written as r1 x r2.

b. The number of attributes in the resulting table is the sum of the number of attributes in both the tables.

c. The number of tuples in the resulting table is the sum of the number of tuples in both the tables.

d. The resulting relation has columns from both the tables and rows that give all possible combinations of rows between the two tables.

Answer:

c. The number of tuples in the resulting table is the sum of the number of tuples in both the tables. (D U/A)

Q. 29. Given a relation - Booklist(BOOK_CODE, NAME, AUTHOR, PRICE)

The select statement to show details of books written by A.ROY is -

a. (Booklist) s _{AUTHOR = “A.ROY”}

b. (Booklist) _{AUTHOR = “A.ROY”} s

c. s _{AUTHOR = “A.ROY”} (Booklist)

d. s (Booklist) _{AUTHOR = “A.ROY”}

Answer:

c. s _{AUTHOR = “A.ROY”} (Booklist) (D U/A)

Q. 30. Given a relation - Booklist(BOOK_CODE, NAME, AUTHOR, PRICE)

The Relational Algebra statement to show NAME and PRICE of books written by A.ROY is -

a. s _{AUTHOR = “A.ROY”} (Π _{NAME, PRICE} (Booklist) )

b. Π _{NAME, PRICE} ( s _{AUTHOR = “A.ROY”} (Booklist) )

c. s _{AUTHOR = “A.ROY”} (Π _{NAME, PRICE}) (Booklist)

d. Π _{NAME, PRICE} (Booklist) ( s _{AUTHOR = “A.ROY”})

Answer:

b. Π _{NAME, PRICE} ( s _{AUTHOR = “A.ROY”} (Booklist) ) (D U/A)

Q. 31. A NULL value is

a. equal to zero (0

b. same as blank spaces

c. an unknown value

d. same as special characters

Answer:

c. an unknown value (E U/A)

Q. 32. After project operation

a. duplicate rows are automatically removed

b. columns appear in the same order as in the table

c. rows satisfying a condition are displayed

d. conditions are specified

Answer:

a. duplicate rows are automatically removed (E U/A)

Q. 33. Which of the following does not apply to union-compatibility?

a. Degree of the relations must be the same

b. Cardinality of the relations must be the same

c. Corresponding domains must be the same

d. A new resultant relation is created

Answer:

b. Cardinality of the relations must be the same (E U/A)

Q. 34. In Relational data model,

a. records are organized as trees

b. records are connected by links

c. data is organized into tables

d. data security cannot be ensured

Answer:

c. data is organized into tables (D U/A)

Q. 35. In Network data model,

a. records are organized as trees

b. records are connected by links

c. data is organized into tables

d. data modification cannot be performed

Answer:

b. records are connected by links (D U/A)

Q. 36. In Hierarchical data model,

a. records are organized as trees

b. records are connected by links

c. data is organized into tables

d. data security cannot be ensured

Answer:

a. records are organized as trees (D U/A)

Q. 37. Given a relation - Product(PRODCODE, NAME, SUPPLIER, PRICE)

The select statement to show details of products priced above 100 is-

a. ( Product ) s _{PRICE > 100}

b. ( Product ) Π _{PRICE > 100}

c. s _{PRICE > 100} ( Product)

d. Π _{PRICE > 100} ( Product)

Answer:

c. s _{PRICE > 100} ( Product) (D U/A)

Q. 38. Given a relation - Product(PRODCODE, NAME, SUPPLIER, PRICE)

The Relational Algebra statement to show Product code and Name of all products is -

a. Π _{PRODCODE, NAME} (Product)

b. (Product) Π _{PRODCODE, NAME}

c. s _{PRODCODE, NAME} (Product)

d. (Product) s _{PRODCODE, NAME}

Answer:

a. Π _{PRODCODE, NAME} (Product) (D U/A)

Q. 39. Given a relation - Product(PRODCODE, NAME, SUPPLIER, PRICE)

The Relational Algebra statement to show Product code and Name of products supplied by “VXL Suppliers” is -

a. s _{PRODCODE, NAME} (Π _{SUPPLIER = “VXL Suppliers”} (Product) )

b. Π _{PRODCODE, NAME} ( s _{SUPPLIER = “VXL Suppliers”} (Product) )

c. Π _{PRODCODE, NAME} (Product) s _{SUPPLIER = “VXL Suppliers”} (Product)

d. ( s _{SUPPLIER = “VXL Suppliers”} (Product) Π _{PRODCODE, NAME} )

Answer:

b. Π _{PRODCODE, NAME} ( s _{SUPPLIER = “VXL Suppliers”} (Product) ) (D U/A)

Q. 40. Given a relation - Product(PRODCODE, NAME, SUPPLIER, PRICE)

The Relational Algebra statement to show Product Name and Price of products supplied by “QWIK” priced more than 100 is -

a. Π _{PRODCODE, PRICE} ( s _{SUPPLIER = “QWIK” && PRICE > 100} (Product) )

b. s _{PRODCODE, PRICE} (Π _{SUPPLIER = “QWIK” ^ PRICE > 100} (Product) )

c. Π _{SUPPLIER = “QWIK” ^ PRICE > 100} s _{PRODCODE, PRICE} (Product)

d. Π _{PRODCODE, PRICE} ( s _{SUPPLIER = “QWIK” ^ PRICE > 100} (Product) )

Answer:

d. Π _{PRODCODE, PRICE} ( s _{SUPPLIER = “QWIK” ^ PRICE > 100} (Product) ) (D U/A)