21. In what tree, for every node the height of its left subtree and right subtree differ at least by one:
(A) Binary search tree (B) AVL tree
(C) Threaded binary tree (D) Complete tree
22. A hash function f defined as f(key) = key mod 7, with linear probing it is used to insert the key 37, 38, 72, 48, 98, 11, 56 into a table index from 0 to 6. What will be the locations of 11?
(A) 3 (B) 4
(C) 5 (D) 6
23. Consider the graph, which of the following is a valid topological sorting?
(A) ABCD (B) BACD
(C) BADC (D) ABDC
24. The initial configuration of queue is a, b, c, d. ‘a’ is at the front. To get the configuration d, c, b, a how many deletions and additions required:
(A) 2 deletions, 3 additions
(B) 3 deletions, 2 additions
(C) 3 deletions, 4 additions
(D) 3 deletions, 3 additions
25. Which traversal technique lists the nodes of a binary search tree in ascending order?
(A) post-order (B) in-order
(C) pre-order (D) linear-order
26. The data unit in the TCP/IP application layer is called a ...............
(A) message (B) segment
(C) datagram (D) frame
27. Which of following file retrieval methods use hypermedia?
(A) HTML (B) Veronica
(C) WAIS (D) HTTP
28. Which of following is an example of a client-server model?
(A) DNS (B) FTP
(C) TELNET (D) All the above
29. ................. points provide a method to recover data that has been delivered but not yet used.
30. Encryption and decryption are the functions of the ................... layer of OSI model.
(A) transport (B) session
(C) router (D) presentation