Q#1: Functional dependency in a database is used to:
(A) Encrypt data
(B) Define relationship between attributes
(C) Delete rows
(D) Store multiple tables
Answer: (B) Define relationship between attributes
Q#2: In a functional dependency X → Y, Y is:
(A) Determinant
(B) Dependent on X
(C) Independent
(D) Composite key
Answer: (B) Dependent on X
Q#3: In a functional dependency X → Y, X is called:
(A) Dependent
(B) Determinant
(C) Candidate key
(D) Surrogate key
Answer: (B) Determinant
Q#4: If X → Y and Y → Z, then X → Z is called:
(A) Reflexive rule
(B) Transitive rule
(C) Augmentation
(D) Union rule
Answer: (B) Transitive rule
Q#5: The functional dependency X → X is called:
(A) Transitive rule
(B) Reflexive rule
(C) Augmentation
(D) Pseudotransitive
Answer: (B) Reflexive rule
Q#6: Which of the following is Armstrong’s axiom?
(A) Reflexivity
(B) Augmentation
(C) Transitivity
(D) All of the above
Answer: (D) All of the above
Q#7: If X → Y, then XZ → YZ is called:
(A) Union
(B) Augmentation
(C) Decomposition
(D) Transitivity
Answer: (B) Augmentation
Q#8: If X → Y and X → Z, then X → YZ is called:
(A) Union
(B) Augmentation
(C) Decomposition
(D) Transitivity
Answer: (A) Union
Q#9: If X → YZ, then X → Y and X → Z is called:
(A) Union
(B) Decomposition
(C) Augmentation
(D) Transitivity
Answer: (B) Decomposition
Q#10: If X → Y and WY → Z, then WX → Z is called:
(A) Union
(B) Augmentation
(C) Pseudotransitivity
(D) Reflexivity
Answer: (C) Pseudotransitivity
Q#11: Trivial functional dependency is:
(A) Y ⊆ X in X → Y
(B) Y ⊄ X
(C) Always null
(D) Never occurs
Answer: (A) Y ⊆ X in X → Y
Q#12: Non-trivial functional dependency is:
(A) Y ⊆ X
(B) Y ⊄ X
(C) Always null
(D) Determinant is null
Answer: (B) Y ⊄ X
Q#13: Fully functional dependency occurs when:
(A) Attribute depends on only part of composite key
(B) Attribute depends on entire key
(C) Attribute depends on non-key attribute
(D) Attribute depends on nothing
Answer: (B) Attribute depends on entire key
Q#14: Partial dependency occurs when:
(A) Attribute depends on whole key
(B) Attribute depends on part of composite key
(C) Attribute depends on non-key
(D) Attribute depends on surrogate key
Answer: (B) Attribute depends on part of composite key
Q#15: Transitive dependency occurs when:
(A) Non-prime attribute depends on primary key via another non-prime attribute
(B) Attribute depends on part of key
(C) Attribute depends on determinant
(D) Attribute depends on null
Answer: (A) Non-prime attribute depends on primary key via another non-prime attribute
Q#16: Functional dependency helps in:
(A) Normalization
(B) Denormalization
(C) Encryption
(D) Backup
Answer: (A) Normalization
Q#17: The closure of a set of attributes X, denoted X⁺, is:
(A) All attributes determined by X
(B) Subset of X
(C) Only keys
(D) Null
Answer: (A) All attributes determined by X
Q#18: Candidate key can be found using:
(A) Functional dependencies
(B) Unique constraints only
(C) Foreign keys only
(D) Surrogate keys only
Answer: (A) Functional dependencies
Q#19: Superkey is:
(A) Set of attributes that uniquely identifies a tuple
(B) Always minimal
(C) Never minimal
(D) Dependent attribute
Answer: (A) Set of attributes that uniquely identifies a tuple
Q#20: Primary key is:
(A) A minimal superkey
(B) Always composite
(C) Foreign key
(D) Non-unique
Answer: (A) A minimal superkey
Q#21: Determinant is:
(A) Attribute on left-hand side of functional dependency
(B) Attribute on right-hand side
(C) Null attribute
(D) Composite key only
Answer: (A) Attribute on left-hand side of functional dependency
Q#22: Trivial dependency is always:
(A) Non-informative
(B) Informative
(C) Illegal
(D) Composite key
Answer: (A) Non-informative
Q#23: Non-trivial dependency provides:
(A) Useful information about attribute relationship
(B) No information
(C) Null value
(D) Surrogate key
Answer: (A) Useful information about attribute relationship
Q#24: Full functional dependency violation occurs in:
(A) 2NF
(B) 3NF
(C) BCNF
(D) 1NF
Answer: (A) 2NF
Q#25: Transitive dependency violation occurs in:
(A) 2NF
(B) 3NF
(C) BCNF
(D) 1NF
Answer: (B) 3NF
Q#26: Functional dependencies are essential to:
(A) Ensure entity integrity
(B) Define keys and normalization
(C) Delete rows
(D) Increase redundancy
Answer: (B) Define keys and normalization
Q#27: Attribute closure helps to:
(A) Find superkeys
(B) Find dependent attributes
(C) Find candidate keys
(D) All of the above
Answer: (D) All of the above
Q#28: BCNF is achieved when:
(A) Every determinant is a candidate key
(B) Partial dependencies exist
(C) Transitive dependencies exist
(D) Table is unnormalized
Answer: (A) Every determinant is a candidate key
Q#29: Functional dependencies are derived from:
(A) Business rules
(B) Database schema
(C) Data relationships
(D) All of the above
Answer: (D) All of the above
Q#30: The main purpose of functional dependencies is:
(A) Data redundancy
(B) Data integrity and normalization
(C) Faster queries
(D) Encryption
Answer: (B) Data integrity and normalization