# UGC NET Computer Science Paper II June 2011 - Part 3

21.       The number of different trees with 8 nodes is
(A) 256               (B) 255
(C) 248              (D) None of these
22.       Given a binary tree whose inorder and preorder traversal are given by
Inorder  : EICFBGDJHK
Preorder : BCEIFDGHJK
The post order traversal of the above binary tree is
(A) IEFCGJKHDB        (B) IEFCJGKHDB
(C) IEFCGKJHDB       (D) IEFCGJKDBH
23.       The number of disk accesses performed by insertion operation in B-tree of height h is
(A) 0(1)              (B) 0(1gh)
(C) 0(h)              (D) None of these
24.       Consider a hash table of size m = 10000 and the hash function h(k) = ∟m(kA mod 1)'┘ for A = (√5–1)/2. The location to the key k = 123456 is
(A) 46                 (B) 47
(C) 41                 (D) 43
25.       When the priority queue is represented by max heap, the insertion and deletion of an element can be performed in (queue containing n elements)
(A) q(n) and q(1) respectively
(B) q(n) and q(n) respectively
(C) q(1) and q(1) respectively
(D) None of the above

26.       A comparison of frequency division and time division multiplexing system shows that
(A) FDM requires a lower bandwidth, but TDM has greater noise immunity.
(B) FDM has greater noise immunity and requires lower bandwidth than TDM.
(C) FDM requires channel synchronization, while TDM has greater noise immunity.
(D) FDM requires more multiplex while TDM requires band pass filter.
27.       If carrier modulated by a digital bit stream, has one one of the possible phase of 0, 90, 180 and 270 degrees, then modulation called
(A) BPSK          (B) QPSK
(C) QAM            (D) MSK
28.       Consider the following statement :
(i) The bandwidth of the A.M., wave depends on the band width of the modulating signal.
(ii) The bandwidth of the A.M., wave depends on the modulation index.
(iii) The bandwidth of the F.M, wave for all practical purpose depends on the amplitude of the carrier. Of these statements the correct statements are
(A) (i, ii)              (B) (i, iii)
(C) (ii, iii)            (D) All of the above
29.       A smart modem can dial, hangup and answer incoming calls automatically. Can you tell who provides the appropriate instructions to the modem for this purpose ?
(A) Communication software
(B) Error detection protocols