GATE CSE 2016 SET-2
Q21.
Consider the following languages: L_{1}=\{a^{n}b^{m}c^{n+m}:m,n\geq 1\} L_{2}=\{a^{n}b^{n}c^{2n}:n\geq 1\} Which one of the following is TRUE?Q22.
Consider the following types of languages: L_{1}:Regular, L_{2}:Context-free, L_{3}:Recursive, L_{4}:Recursively enumerable. Which of the following is/are TRUE? I. \bar{L}_{3}\cup L_{4} is recursivelyenumerable II. \bar{L}_{2}\cup L_{3} is recursive III. L_{1}^{*}\cup L_{2} is context-free IV. L_{1}\cup \bar{L}_{2} is context-freeQ24.
Consider the following processes, with the arrival time and the length of the CPU burst given in milli seconds.The scheduling algorithm used is preemptive shortest remaining-time first. The average turn around time of these processes is milliseconds.Q25.
Consider a 128 \times 10^{3} bits/second satellite communication link with one way propagation delay of 150 milliseconds. Selective retransmission(repeat) protocol is used on this link to send data with a frame size of 1 kilobyte. Neglect the transmission time of acknowledgement. The minimum number of bits required for the sequence number field to achieve 100% utilization is ________.Q26.
For the IEEE802.11 MAC protocol for wireless communication,which of the following statements is/are TRUE? I. At least three non-overlapping channels are available for transmissions. II. The RTS-CTS mechan is misused for collision detection. III. Unicast frames are ACKed.Q28.
A network has a data transmission bandwidth of 20 \times 10^{6} bits per second. It uses CSMA/CD in the MAClayer. The maximum signal propagation time from one node to another node is 40 microseconds. The minimum size of a frame in the network is ______ bytes.Q29.
Let, x_{1} \oplus x_{2} \oplus x_{3} \oplus x_{4}=0 where x_{1}, x_{2} , x_{3} , x_{4} are Boolean variables, and \oplus is the XOR operator. Which one of the following must always be TRUE?