GATE CSE 2018
Q51.
Consider the following two tables and four queries in SQL. Which one of the queries above is certain to have an output that is a superset of the outputs of the other three queries?Q52.
Consider the following problems. L(G) denotes the language generated by a grammar G. L(M) denotes the language accepted by a machine M. (I) For an unrestricted grammar G and a string w, whether w\in L(G) (II) Given a Turing machine M, whether L(M) is regular (III) Given two grammars G1 and G2, whether L(G1) = L(G2) (IV) Given an NFA N, whether there is a deterministic PDA P such that N and P accept the same language. Which one of the following statements is correct?Q53.
Consider the following statements regarding the slow start phase of the TCP congestion control algorithm. Note that cwnd stands for the TCP congestion window and MSS denotes the Maximum Segment Size. (i) The cwnd increases by 2 MSS on every successful acknowledgment. (ii) The cwnd approximately doubles on every successful acknowledgement. (iii) The cwnd increases by 1 MSS every round trip time. (iv) The cwnd approximately doubles every round trip time. Which one of the following is correct?Q55.
Consider a long-lived TCP session with an end-to-end bandwidth of 1 Gbps (= 10^{9} bits-per-second). The session starts with a sequence number of 1234. The minimum time (in seconds, rounded to the closest integer) before this sequence number can be used again is _______.Q56.
Consider the sequential circuit shown in the figure, where both flip-flops used are positive edge-triggered D flip-flops. The number of states in the state transition diagram of this circuit that have a transition back to the same state on some value of "in" is _____.