# Data Structure MCQ Questions

This section focuses on "basics" of Data Structure. These Multiple Choice Questions (MCQ) should be practiced to improve the Data Structure skills required for various interviews (campus interviews, walk-in interviews, company interviews), placements, entrance exams and other competitive examinations.

1. How many cases are there, which are used to compare various data structure's execution time in a relative manner?

A. 2

B. 3

C. 4

D. 5

View Answer

Ans : B

Explanation: There are three cases which are usually used to compare various data structure's execution time in a relative manner : Worst Case ,Average Case and Best Case.

2. Which case of data structure operation takes maximum time?

A. Worst Case

B. Average Case

C. Best Case

D. None of the above

View Answer

Ans : A

Explanation: Worst Case : This is the scenario where a particular data structure operation takes maximum time it can take.

3. In Average case, if operation takes ƒ(n) time in execution, then m operations will take?

A. ƒ(n)

B. f(m)

C. mf(n)

D. nf(m)

View Answer

Ans : C

Explanation: If an operation takes ƒ(n) time in execution, then m operations will take mƒ(n) time.

4. __________ is a single elementary unit of information representing an attribute of an entity.

A. Entity Set

B. Record

C. File

D. Field

View Answer

Ans : D

Explanation: Field is a single elementary unit of information representing an attribute of an entity.

5. What is true about Interface in data structure?

A. Each data structure has an interface.

B. Interface represents the set of operations that a data structure supports.

C. An interface only provides the list of supported operations, type of parameters they can accept and return type of these operations.

D. All of the above

View Answer

Ans : D

Explanation: Interface : Each data structure has an interface. Interface represents the set of operations that a data structure supports. An interface only provides the list of supported operations, type of parameters they can accept and return type of these operations.

6. Which of the following is not a Characteristics of a Data Structure?

A. Completeness

B. Correctness

C. Time Complexity

D. Space Complexity

View Answer

Ans : A

Explanation: Completeness is not a Characteristics of a Data Structure.

7. Which characteristics shows that running time or the execution time of operations of data structure must be as small as possible?

A. Completeness

B. Correctness

C. Time Complexity

D. Space Complexity

View Answer

Ans : C

Explanation: Time Complexity : Running time or the execution time of operations of data structure must be as small as possible.

8. Data items that cannot be divided are called as?

A. Group Items

B. Attribute and Entity

C. Elementary Items

D. File items

View Answer

Ans : C

Explanation: Data items that cannot be divided are called as Elementary Items.

9. Which of the following analysis known as theoretical analysis of an algorithm?

A. A Posterior Analysis

B. A Priori Analysis

C. A Feasibility Analysis

D. A Independent Analysis

View Answer

Ans : B

Explanation: A Priori Analysis : This is a theoretical analysis of an algorithm. Efficiency of an algorithm is measured by assuming that all other factors, for example, processor speed, are constant and have no effect on the implementation.

10. Which of the following analysis known as empirical analysis of an algorithm?

A. A Posterior Analysis

B. A Priori Analysis

C. A Feasibility Analysis

D. A Independent Analysis

View Answer

Ans : A

Explanation: A Posterior Analysis : This is an empirical analysis of an algorithm. The selected algorithm is implemented using programming language. This is then executed on target computer machine. In this analysis, actual statistics like running time and space required, are collected.

11. An algorithm should have _________ well-defined outputs

A. 0

B. 1

C. 0 or more

D. 1 or more

View Answer

Ans : D

Explanation: An algorithm should have 1 or more well-defined outputs, and should match the desired output.

12. __________ of an algorithm represents the amount of memory space required by the algorithm in its life cycle.

A. Space complexity

B. Time Complexity

C. Quadratic Complexity

D. Exponential Complexity

View Answer

Ans : A

Explanation: Space complexity of an algorithm represents the amount of memory space required by the algorithm in its life cycle.

13. The space required by an algorithm is equal to the sum of the following _______ components.

A. 1

B. 2

C. 3

D. 4

View Answer

Ans : B

Explanation: The space required by an algorithm is equal to the sum of the following two components : A fixed part that is a space required to store certain data and variables and A variable part is a space required by variables.

14. Which is the formal way to express the upper bound of an algorithm's running time.

A. Big Oh Notation

B. Omega Notation

C. Theta Notation

D. None of the above

View Answer

Ans : A

Explanation: Big Oh Notation : The notation Ο(n) is the formal way to express the upper bound of an algorithm's running time. It measures the worst case time complexity or the longest amount of time an algorithm can possibly take to complete.

15. The Omega notation is the formal way to express the __________ of an algorithms running time.

A. upper bound

B. medium bound

C. lower bound

D. both the lower bound and the upper bound

View Answer

Ans : C

Explanation: The Omega notation is the formal way to express the lower bound of an algorithm's running time. It measures the best case time complexity or the best amount of time an algorithm can possibly take to complete.

Discussion