Showing 81–90 of 94 questions
What is the main disadvantage of using a linked list compared to arrays?
A
Linked lists use more memory due to pointers
B
Linked lists have O(1) insertion at beginning
C
Linked lists cannot be sorted
D
Linked lists have cache locality issues
Correct Answer:
A. Linked lists use more memory due to pointers
Explanation:
Linked lists require extra memory for storing pointers/references in each node, making them memory-inefficient compared to arrays.
In AWS, what does the term 'Auto Scaling' primarily ensure?
A
Automatic backup of databases
B
Automatic adjustment of compute capacity based on demand
C
Automatic encryption of data
D
Automatic software updates
Correct Answer:
B. Automatic adjustment of compute capacity based on demand
Explanation:
AWS Auto Scaling automatically adjusts the number of EC2 instances based on demand metrics like CPU utilization or network traffic.
What is the primary function of a hash table data structure?
A
To maintain sorted data
B
To provide O(1) average-case lookup time using hash functions
C
To implement tree traversal
D
To perform recursive function calls
Correct Answer:
B. To provide O(1) average-case lookup time using hash functions
Explanation:
Hash tables use hash functions to map keys to indices, providing O(1) average-case lookup, insertion, and deletion operations.
What is the time complexity of the binary search algorithm on a sorted array?
A
O(n)
B
O(log n)
C
O(n log n)
D
O(n²)
Correct Answer:
B. O(log n)
Explanation:
Binary search divides the search space in half with each iteration, resulting in O(log n) time complexity on sorted data.
What is the purpose of the COMMIT statement in SQL transactions?
A
To undo all pending changes
B
To save all changes made during a transaction permanently to the database
C
To create a new transaction
D
To delete committed records
Correct Answer:
B. To save all changes made during a transaction permanently to the database
Explanation:
COMMIT saves all changes made during the current transaction to the database permanently. Until COMMIT, changes can be rolled back using ROLLBACK.
Which cryptographic algorithm is currently recommended by NIST for symmetric encryption?
A
DES (Data Encryption Standard)
B
AES (Advanced Encryption Standard)
C
MD5
D
SHA-1
Correct Answer:
B. AES (Advanced Encryption Standard)
Explanation:
AES is the current NIST standard for symmetric encryption with key sizes of 128, 192, or 256 bits. DES is deprecated due to weak key size.
Which SQL JOIN returns only matching records from both tables?
A
INNER JOIN
B
LEFT JOIN
C
RIGHT JOIN
D
FULL OUTER JOIN
Correct Answer:
A. INNER JOIN
Explanation:
INNER JOIN returns only the records that have matching values in both tables, filtering out non-matching rows.
In database indexing, which structure provides O(log n) search complexity?
A
Linear search
B
B-Tree
C
Hash table with collision
D
Linked list
Correct Answer:
B. B-Tree
Explanation:
B-Tree maintains balanced structure ensuring O(log n) search, insert, and delete operations, commonly used in databases.
Which data structure is best for implementing a priority queue in heapsort algorithm?
A
Stack
B
Queue
C
Heap
D
Array
Explanation:
A heap (min-heap or max-heap) efficiently supports priority queue operations with O(log n) insertion and deletion.
What is the main advantage of cloud computing's elasticity?
A
Lower initial hardware cost
B
Automatic resource scaling based on demand
C
Guaranteed 100% uptime
D
Elimination of all security risks
Correct Answer:
B. Automatic resource scaling based on demand
Explanation:
Elasticity allows automatic resource provisioning and de-provisioning based on real-time demand, reducing costs.
