Given the following two statements:

S1: If L1 and L2 are recursively enumerable languages over ∑, then L1⋃L2 and

L1⋂L2 are also recursively enumerable.

S2: The set of recursively enumerable languages is countable.

Which of the following is correct?

(A) S1 is correct and S2 is not correct

(B) S1 is not correct and S2 is correct

(C) Both S1 and S2 are not correct

(D) Both S1 and S2 are correct

1 Answer

Answer :

(D) Both S1 and S2 are correct

Related questions

Description : Which of the following statements is false? (1) Every context-sensitive language is recursive. (2) The set of all languages that are not recursively enumerable is countable. (3) The family ... under union. (4) The families of recursively enumerable and recursive languages are closed under reversal.

Last Answer : The set of all languages that are not recursively enumerable is countable.

Description : The direction of rotation of the winch shown in the illustration is changed by reversing the _____________. EL-0102 A. direction of current through the shunt field B. polarity of voltage at 'S1' and 'S2' C. direction of current through the armature D. polarity of voltage at 'L1' and 'L2'

Last Answer : Answer: C

Description : The statements s1 and s2 are given as: s1: Context sensitive languages are closed under intersection, concatenation, substitution and inverse homomorphism. s2: Context free languages are closed under complementation, ... is not correct and s2 is correct. (D) Both s1 and s2 are not correct.

Last Answer : (B) s1 is correct and s2 is not correct.

Description : Given the following two languages: L1 = {anbn|n≥0, n≠100} L2 = {w ϵ {a,b,c}*| na(w) = nb(w) = nc(w)} Which of the following options is correct? (1) Both L1 and L2 are ... context free language, L2 is not context free language. (4) L1 is not context free language, L2 is context free language.

Last Answer : L1 is context free language, L2 is not context free language.

Description : Given the following statements : S1 : If L is a regular language then the language {uv | uϵL, vϵLR} is also regular. S2 : L = {wwR} is regular language. Which of the following is true ? (A) S1 is not ... S2 is correct. (C) S1 is correct and S2 is not correct. (D) S1 is correct and S2 is correct.

Last Answer : (C) S1 is correct and S2 is not correct.

Description : Consider the languages L1 = ϕ, and L2 = {1}. Which one of the following represents L1* U L2* L1* ? (1) {ε} (2) {ε,1} (3) ϕ (4) 1*

Last Answer : 1*

Description : Given the following statements :  S1 : The subgraph-isomorphism problem takes two graphs G1 and G2 and asks whether G1 is a subgraph of G2.  S2 : The set-partition problem takes as input a set S of numbers and ... S1 is P problem and S2 is P problem. (D) S1 is P problem and S2 is NP problem.

Last Answer : (B) S1 is NP problem and S2 is NP problem.

Description : Given the following statements: S1 : The grammars S→asb | bsa | ss | a and S→asb | bsa | a are not equivalent. S2: The grammars S→ss | sss | asb | bsa | λ and S→ss | asb | bsa | λ are equivalent. ... and S2 are correct (C) S1 is not correct and S2 is correct (D) Both S1 and S2 are not correct.

Last Answer : (A) S1 is correct and S2 is not correct.

Description : Given the following statements: S1: Every context-sensitive language L is recursive. S2: There exists a recursive language that is not context sensitive. Which statement is correct? (A) S1 is not correct and S2 is ... (C) S1 is correct and S2 is not correct. (D) S1 is correct and S2 is correct.

Last Answer : (D) S1 is correct and S2 is correct. 

Description : Given the following statements : S1 : SLR uses follow information to guide reductions. In case of LR and LALR parsers, the look-aheads are associated with the items and they make use of the left context available to ... (C) S1 is correct and S2 is not correct. (D) S1 is correct and S2 is correct.

Last Answer : (D) S1 is correct and S2 is correct.

Description : Consider the following statements : S1: A queue can be implemented using two stacks. S2: A stack can be implemented using two queues. Which of the following is correct ? (A) S1 is correct and S2 is not correct. ( ... S2 is correct. (C) Both S1 and S2 are correct. (D) Both S1 and S2 are not correct.

Last Answer : (C) Both S1 and S2 are correct.

Description : Consider the following statements for priority queue: S1: It is a data structure in which the intrinsic ordering of the elements does determine the result of its basic operations. S2: The elements of a priority queue ... . (C) SI is incorrect and S2 is correct. (D) Both S1 and S2 are correct.

Last Answer : (D) Both S1 and S2 are correct.

Description : Which is the correct statement(s) for Non Recursive predictive parser? S1: First(α) = {t | α => * t β for some string β } => *tβ S2: Follow(X) = { a | S => * αXa β for some strings ... and S2 is correct. (C) S1 is correct and S2 is incorrect. (D) Both statements S1 and S2 are correct. 

Last Answer : (D) Both statements S1 and S2 are correct.

Description : Consider the following statements S1 and S2 : S1 : A hard handover is one in which the channel in the source cell is retained and used for a while in parallel with the channel in the target cell. S2 : A soft handover ... and S2 is true. (C) Both S1 and S2 are true. (D) Both S1 and S2 are not true.

Last Answer : (D) Both S1 and S2 are not true.

Description : A pushdown automation M = (Q, Σ, Γ, δ, q0, z, F) is set to be deterministic subject to which of the following condition(s), for every q ∈ Q, a ∈ Σ ∪ {λ} and b ∈ Γ (s1) δ(q, a, b) contains at most one ... ) must be empty for every c ∈ Σ (A) only s1 (B) only s2 (C) both s1 and s2 (D) neither s1 nor s2

Last Answer : (C) both s1 and s2

Description : Given L1 = L(a*baa*) and L2 = L(ab*) The regular expression corresponding to language L3 = L1/L2 (right quotient) is given by (A) a*b (B) a*baa* (C) a*ba* (D) None of the above

Last Answer : (C) a*ba* 

Description : Which of the following statement(s) is/are true with respect to software architecture? S1: Coupling is a measure of how well the things grouped together in a module belong together logically. S2: Cohesion is a measure of the ... ) Only S1 and S2 (2) Only S3 (3) All of S1, S2 and S3 (4) Only S1

Last Answer : Answer: 2

Description : Consider following schedules involving two transactions: S1: r1(X); r1(Y); r2(X); r2(Y); w2(Y); w1(X) S2: r1(X); r2(X); r2(Y); w2(Y); r1(Y); w1(X) Which of the following ... . (3) S1 is not conflict serializable and S2 is conflict serializable. (4) Both S1 and S2 are not conflict serializable.

Last Answer : S1 is not conflict serializable and S2 is conflict serializable.

Description : Which one of the following statements is correct regarding the GPS satellites? (A) The nominal altitude is about 20,200 km (B) The inclination of axis satellite is 55° (C) The satellite transmits two L band signals (L1 with 1575.42 MHz and L2 with 1276.6 MHz) (D) All of these

Last Answer : Answer: Option D

Description : A compound pipe of diameter d1, d2 and d3 having lengths l1, l2 and l3 is to be replaced by an equivalent pipe of uniform diameter d and of the same length (l) as that of the compound pipe. The size of the equivalent pipe is given by (A) l/d² = + + (B) l/d³ = + ) + (C) = + + (D)

Last Answer : Answer: Option D

Description : Pentium Pro Processor contains: a. L1 Cache b. L2 Cache c. Both L1 & L2 d. None of these

Last Answer : c. Both L1 & L2

Description : Which of the following is/are not true? (a) The set of negative integers is countable. (b) The set of integers that are multiples of 7 is countable. (c) The set of even integers is countable. (d) The set of real numbers between 0 ... . (A) (a) and (c) (B) (b) and (d) (C) (b) only (D) (d) only

Last Answer : (D) (d) only

Description : If = = in the system of equations a 1 x + b 1 y + c 1 = 0 and a 2 x + b 2 y + c 2 = 0 Statement 1 : This is the condition for inconsistent equations Statement 2 : There exists infinitely many solutions ... statements are true ? e) S1 only f) S1 and S2 g) S1 and S3 h) S2 only Answer: (d) S2 o

Last Answer : h) S2 only

Description : If = = in the system of equations a 1 x + b 1 y + c 1 = 0 and a 2 x + b 2 y + c 2 = 0 Statement 1 : This is the condition for inconsistent equations Statement 2 : There exists infinitely many ... parallel Which of the above statements are true ? a) S1 only b) S1 and S2 c) S1 and S3 d) S2 only

Last Answer : d) S2 only

Description : Two lines L1 and L2 having Parametric equations are P1=[3 4 7]+u[2 2 -6] and P2=[15 -2]+u[1 4 2]. Tangent vector for line L1 a.2i+2j-6k b.2i+2j+6k c.2i-2j-6k d.6-2j-2k

Last Answer : a.2i+2j-6k

Description : If l1 and l2 are the lengths of long and short spans of a two way slab simply supported on four edges and carrying a load w per unit area, the ratio of the loads split into w1 and w2acting on strips parallel to l2 and l1 is (A) ... l1 (B) w1/w2 = (l2/l1)² (C) w1/w2 = (l2/l1)3 (D) w1/w2 = (l2/l1)

Last Answer : Answer: Option D

Description : What does conus is seen terminating at the L1-L2 level mean?

Last Answer : What is the answer ?

Description : When an operating motor is connected to the controller shown in the illustration, the a path of current flow through the circuit is ____________. EL-0010 A. 'L1', stop button, start button, coil 'CR', 'L2' B. 'L1' ... L2' D. 'L1', stop button, start button, 'CR' contact, 'M' contact, 'CR' coil, 'L2'

Last Answer : Answer: B

Description : In the illustration if the compressor fails to start but the condenser fan motor is running the problem is _______. EL-0042 A. no power between L1 and L2 B. the yellow wire is open at the freezer temperature control switch C. the overload is open D. the blue wire from the defrost heater is open

Last Answer : Answer: C

Description : In the illustration if the compressor fails to start but the condenser fan motor is running the problem is _______. EL-0043 A. no power between L1 and L2 B. the yellow wire is open at the freezer temperature control switch C. the overload is open D. the blue wire from the defrost heater is open

Last Answer : Answer: C

Description : In an emergency, the fastest way to interrupt power and stop the winch shown in the illustration is for the ____________. EL-0102 A. mate to open the disconnect switch at 'L1' and 'L2' B. ... watch engineer to open the winch circuit breaker D. electrician to open the test link at the controller

Last Answer : Answer: B

Description : The horizontal angles from the boat between A and B and B and C, the stations on the shore are 1 2. The distances AB = L1 and BC = L2 2 at C between the boat and station B between A and C at B). (A) 1 2) = (L2 1/L1 2) = K (B) t 2 = 360° - 1 2 (C) 2 = sin /(K + ) (D) All the above

Last Answer : (D) All the above

Description : The total extension in a bar, consists of 3 bars of same material, of varying sections is a. P/E(L1/A1+L2/A2+L3/A3) b. P/E(L1A1+L2A2+L3A3) c. PE(L1/A1+L2/A2+L3/A3) d. PE(L1/A1+L2/A2+L3/A3)

Last Answer : a. P/E(L1/A1+L2/A2+L3/A3)

Description : Given the following statements : (A) A class of languages that is closed under union and complementation has to be closed under intersection. (B) A class of languages that is closed under union and intersection has to be closed under ... (3) (A) is true, (B) is false. (4) (A) is false, (B) is true.

Last Answer : (A) is true, (B) is false. 

Description : Given the following Series S1 and S2: Write the command to find the sum of series S1 and S2 -Technology

Last Answer : print(S1+S2)

Description : If S1 is total number of modules defined in the program architecture, S3 is the number of modules whose correct function depends on prior processing then the number of modules not dependent on prior processing is: (A) 1 + S3/S1 (B) 1 - S3/S1 (C) 1 + S1/S3 (D) 1 - S1/S3

Last Answer : (B) 1 - S3/S1

Description : If coils 'R1-R2-R3' at the receiver of figure 'B' shown in the illustration turned opposite of those in the transmitter, what corrective action should be taken to have both turn in the same direction? EL-0092 A ... is needed. C. Interchange leads 'R1' and 'R3'. D. Interchange leads 'R2' and 'R3'.

Last Answer : Answer: C

Description : [31] With both S1 and S2 open, the core flux waveform will be [GATE 2009] A. a sinusoidal at fundamental frequency B. flat-topped with third harmonic C. peaky with third-harmonic D. none of these

Last Answer : B. Flat topped with third harmonic

Description : Which of the following statements is true? (1) The sentence S is a logical consequence of S1,..., Sn if and only if S1˄S2˄........˄Sn→S is satisfiable. (2) The sentence S is a logical consequence of ... S is a logical consequence of S1,..., Sn if and only if S1˄S2˄........˄Sn˄S is inconsistent.

Last Answer : The sentence S is a logical consequence of S1,..., Sn if and only if S1˄S2˄........˄Sn→S is valid.

Description : If coils 'R1-R2-R3' at the receiver of figure 'B' shown in the illustration turned opposite of those in the transmitter by design, what corrective action should be taken? EL-0092 A. Reverse the 60 Hz supply ... is needed. C. Interchange leads 'R1' and 'R3'. D. Interchange leads 'R2' and 'R3'.

Last Answer : Answer: B

Description : If coils 'R1-R2-R3' at the receiver of figure 'B' shown in the illustration were in 180 degree error with those of the transmitter, what corrective action should be taken? EL-0092 A. Reverse the 60 Hz ... is proper operation. C. Interchange leads 'R1' and 'R3'. D. Interchange leads 'R2' and 'R3'.

Last Answer : Answer: A

Description : If coil 'R1-R2' at the receiver of figure 'A' shown in the illustration were in 180 degree error with respect to that of the transmitter, what corrective action should be taken? EL-0092 A. No action is ... and 'R2'. C. Interchange connections 'S1' and 'S2'. D. Interchange connections 'S1' and 'S3'.

Last Answer : Answer: B

Description : If coil 'R1-R2' at the receiver of figure 'A' shown in the illustration turned opposite of that in the transmitter, what corrective action should be taken? EL-0092 A. No action is necessary as this is ... . C. Interchange connections to 'S1' and 'S2'. D. Interchange connections to 'S1' and 'S3'.

Last Answer : Answer: D

Description : If coil 'R1-R2' on the transmitter in figure 'A' shown in the illustration is turned 30 degrees clockwise, corresponding coil 'R1-R2' on the receiver should ____________. EL-0092 A. make coils 'S1 ... a higher voltage depending on the turns ratio D. align itself to the same position if free to move

Last Answer : Answer: D

Description : Derivation of Thiem's formula Q = 2 (s1 - s2)/2.3 log10 (r2/r1) is based on the assumption  (A) The aquifer is homogeneous, isotropic and of infinite depth and area  (B) The well is sunk ... (C) The flow lines are radial and horizontal, and the flow is laminar  (D) All the above 

Last Answer : (D) All the above 

Description : S1 and S2 are the draw downs in an observation well at times t1 and t2 after pumping. For  discharge Q and coefficient of transmissibility T, the relationship, is  (A) S2 - S1 = (2.3Q/ ) log10 (t2/t1)  (B) S2 - S1 ... - S1 = (2.3Q/4 ) loge (t2/t1)  (D) S2 - S1 = (2.3Q/4 ) loge (t1/t2

Last Answer : (B) S2 - S1 = (2.3Q/4 ) log10 (t2/t1) 

Description : the derivation of Thiem's formula, Q = (S1 - S2)/[2.3 log10( / )] the following assumption is not applicable (A) The aquifer is homogeneous and isotropic (B) Flow lines are radial and ... the water surface is too small (D) The well has been sunk up to the surface of the unconfined aquifer

Last Answer : Answer: Option D