gate questions

Q. Consider the following grammar and the semantic actions to support the inherited type declaration attributes. Let 𝑋1, 𝑋2, 𝑋3, 𝑋4, 𝑋5, and 𝑋6 be the placeholders for the non- terminals D, T, L or L1 in the following table: Production rule Semantic action D → T L 𝑋1.type = 𝑋2.type T → int T.type […]

Q. Consider the first order predicate formula 𝜑: ∀𝑥 [(∀𝑧 𝑧|𝑥 ⇒ ((𝑧 = 𝑥) ∨ (𝑧 = 1))) ⇒ ∃𝑤 (𝑤 > 𝑥) 𝖠 (∀𝑧 𝑧|𝑤 ⇒ ((𝑤 = 𝑧) ∨ (𝑧 = 1)))] Here ‘𝑎|𝑏’ denotes that ‘𝑎 divides 𝑏’, where 𝑎 and 𝑏 are integers. Consider the following sets: S1.       {1,2,3, …

Q. Consider the following sets: S1.       Set of all recursively enumerable languages over the alphabet {0,1} S2.       Set of all syntactically valid C programs S3.        Set of all languages over the alphabet {0,1} S4.       Set of all non-regular languages over the alphabet {0,1} Which of the above sets are uncountable? (A) S1 and S2 (B) S3

Q. Assume that in a certain computer, the virtual addresses are 64 bits long and the physical addresses are 48 bits long. The memory is word addressible. The page size is 8 kB and the word size is 4 bytes. The Translation Look-aside Buffer (TLB) in the address translation path has 128 valid entries. At

Q. Let the set of functional dependencies F = {QR → S, R → P, S → Q} hold on a relation schema X = (PQRS). X is not in BCNF. Suppose X is decomposed into two schemas Y and Z, where Y = (PR) and Z = (QRS). Consider the two statements given below.

Q. Which one of the following languages over Σ = {𝑎, 𝑏} is NOT context-free? (A) {𝑤𝑤𝑅 |𝑤 ∈ {𝑎, 𝑏}∗} (B) {𝑤𝑎𝑛𝑏𝑛𝑤𝑅 |𝑤 ∈ {𝑎, 𝑏}∗, 𝑛 ≥ 0} (C) {𝑤𝑎𝑛𝑤𝑅𝑏𝑛 |𝑤 ∈ {𝑎, 𝑏}∗, 𝑛 ≥ 0} (D) {𝑎𝑛𝑏𝑖 | 𝑖 ∈ {𝑛, 3𝑛, 5𝑛}, 𝑛 ≥ 0} Ans: {wanwRbn ⏐ w ∈ {a,

Q. Suppose that in an IP-over-Ethernet network, a machine X wishes to find the MAC address of another machine Y in its subnet. Which one of the following techniques can be used for this? A. X sends an ARP request packet to the local gateway’s IP address which then finds the MAC address of Y

Q. Consider three machines M, N, and P with IP addresses 100.10.5.2, 100.10.5.5, and 100.10.5.6 respectively. The subnet mask is set to 255.255.255.252 for all the three machines. Which one of the following is true? (A) M, N, and P all belong to the same subnet (B) Only M and N belong to the same

Q. Two numbers are chosen independently and uniformly at random from the set {1, 2 , . . . , 13}. The probability (rounded off to 3 decimal places) that their 4-bit (unsigned) binary representations have the same most significant bit is Solution: The 4-bit binary representation of numbers (1, 2, 3, 4………13): 0  –

Q. The value of 351 mod 5 is     . Solution: = 351 mod 5 = (33)17 mod 5 = (27)17 mod 5= {(22)8*21} mod 5= {(4)8*(2)} mod 5= {(-1)8*(2)} mod 5= {(1*2)} mod 5= {(2)} mod 5= 2