Olete.in – MCQs, Mock Tests & Government Job Prep | Gate GATE 2017-2018 Aeronautical

The constraint A2 = A on any square matrix A is satisfied for

1. the identity matrix only
2. the null matrix only
3. both the identity matrix and the null matrix.
4. no square matrix A.

✅ Correct Answer: 3

The general solution of the different equation d2y/dt2 + dy/dt - 2t = 0 is

1. Ae-t + Be2t
2. Ae-2t + Be-t
3. Ae-2t + Bet
4. Aet + Be2t

✅ Correct Answer: 3

An aircraft in trimmed condition has zero pitching moment at

1. its aerodynamic centre
2. its centre of gravity
3. 25% of its mean aerodynamic chord.
4. 50% of its wing root chord.

✅ Correct Answer: 2

In an aircraft, constant roll rate can be produced using ailerons by applying

1. a step input.
2. a ramp input.
3. a sinusoidal input
4. an impulse input.

✅ Correct Answer: 4

For a symmetric airfoil, the lift coefficient for zero degree angle of attack is

1. "“ 1.0
2. 0.0
3. 0.5
4. 1.0

✅ Correct Answer: 2

The critical Mach number of an airfoil is attained when

1. the freestream Mach number is sonic.
2. the freestream Mach number is supersonic
3. the Mach number somewhere on the airfoil is unity.
4. the Mach number everywhere on the airfoil is supersonic.

✅ Correct Answer: 3

The Hohmann ellipse used as earth-Mars transfer orbit has

1. apogee at earth and perigee at Mars
2. both apogee and perigee at earth.
3. apogee at Mars and perigee at earth.
4. both apogee and perigee at Mars.

✅ Correct Answer: 3

Which of the following is TRUE?

1. Every relation in 3NF is also in BCNF
2. A relation R is in 3NF if every non-prime attribute of R is fully functionally dependent on every key of R
3. Every relation in BCNF is also in 3NF
4. No relation can be in both BCNF and 3NF

✅ Correct Answer: 3

Assuming P â‰ NP, which of the following is TRUE?

1. NP-complete = NP
2. NP-complete âˆ© P = Ï†
3. NP-hard = NP
4. P = NP-complete

✅ Correct Answer: 2

The worst case running time to search for an element in a balanced binary search tree with n2n elements is

1. Î˜ (n log n)
2. Î˜ (n2n)
3. Î˜ (n)
4. Î˜ (log n)

✅ Correct Answer: 3

A process executes the code fork(); fork(); fork(); The total number of child processes created is

1. 3
2. 4
3. 7
4. 8

✅ Correct Answer: 3

Consider the function f(x) = sin(x) in the interval x Ïµ [Ï€/4, 7Ï€/4]. The number and location(s) of the local minima of this function are

1. One, at Ï€/2
2. One, at 3Ï€/2
3. Two, at Ï€/2 and 3Ï€/2
4. Two, at Ï€/4 and 3Ï€/2

✅ Correct Answer: 4

The protocol data unit (PDU) for the application layer in the Internet stack is

1. Segment
2. Datagram
3. Message
4. Frame

✅ Correct Answer: 3

Let A be the 2 * 2 matrix with elements a11 = a12 = a21 = +1 and a22 = -1. Then the eigenvalues of the matrix A19 are

1. 1024 and âˆ’1024
2. 1024√2 and âˆ’1024√2
3. 4√2 and âˆ’4√2
4. 512√2 and âˆ’512√2

✅ Correct Answer: 4

What is the correct translation of the following statement into mathematical logic? "Some real numbers are rational

1. ÆŽx (real(x) á´ rational(x))
2. ÆŽx (real(x) â†’ rational(x))
3. ÆŽx (real(x) á´§ rational(x))
4. ÆŽx (rational(x) â†’ real(x))

✅ Correct Answer: 3

Given the basic ER and relational models, which of the following is INCORRECT?

1. An attribute of an entity can have more than one value
2. An attribute of an entity can be composite
3. In a row of a relational table, an attribute can have more than one value
4. In a row of a relational table, an attribute can have exactly one value or a NULL value

✅ Correct Answer: 3

Which of the following statements are TRUE about an SQL query? P : An SQL query can contain a HAVING clause even if it does not have a GROUP BY clause Q: An SQL query can contain a HAVING clause only if it has a GROUP BY clause R : All attributes used in the GROUP BY clause must appear in the SELECT clause S : Not all attributes used in the GROUP BY clause need to appear in the SELECT clause

1. P and R
2. P and S
3. Q and R
4. Q and S

✅ Correct Answer: 3

The recurrence relation capturing the optimal execution time of the Towers of Hanoi problem with n discs is

1. T(n) = 2T(n âˆ’ 2) + 2
2. T(n) = 2T(n âˆ’ 1) + n
3. T(n) = 2T(n/2) + 1
4. T(n) = 2T(n âˆ’ 1) + 1

✅ Correct Answer: 4

Let G be a simple undirected planar graph on 10 vertices with 15 edges. If G is a connected graph, then the number of bounded faces in any embedding of G on the plane is equal to

1. 3
2. 4
3. 5
4. 6

✅ Correct Answer: 4

Let W(n) and A(n) denote respectively, the worst case and average case running time of an algorithm executed on an input of size n. Which of the following is ALWAYS TRUE?

1. A(n) = Î© (W(n))
2. A(n) = Î˜ (W(n))
3. A(n) = O (W(n))
4. A(n) = o (W(n)

✅ Correct Answer: 3

The amount of ROM needed to implement a 4 bit multiplier is

1. 64 bits
2. 128 bits
3. 1 Kbits
4. 2 Kbits

✅ Correct Answer: 4

Register renaming is done in pipelined processors

1. as an alternative to register allocation at compile time
2. for efficient access to function parameters and local variables
3. to handle certain kinds of hazards
4. as part of address translation

✅ Correct Answer: 3

Consider a random variable X that takes values +1 and âˆ’1 with probability 0.5 each. The values of the cumulative distribution function F(x) at x = âˆ’1 and +1 are

1. 0 and 0.5
2. 0 and 1
3. 0.5 and 1
4. 0.25 and 0.75

✅ Correct Answer: 3

Which of the following transport layer protocols is used to support electronic mail?

1. SMTP
2. IP
3. TCP
4. UDP

✅ Correct Answer: 3

Which of the following problems are decidable? 1) Does a given program ever produce an output? 2) If L is a context-free language, then, is also context-free? 3) If L is a regular language, then, is also regular? 4) If L is a recursive language, then, is also recursive?

1. 1, 2, 3, 4
2. 1, 2
3. 2, 3, 4
4. 3, 4

✅ Correct Answer: 4

Given the language L = {ab, aa, baa}, which of the following strings are in L*?

1. abaabaaabaa
2. aaaabaaaa
3. baaaaabaaaab
4. baaaaabaa

✅ Correct Answer: 3

The bisection method is applied to compute a zero of the function f(x) = x4 - x3 - x2 - 4 in the interval [1,9]. The method converges to a solution after “““““ iterations

1. 1
2. 3
3. 5
4. 7

✅ Correct Answer: 2

Fetch_And_Add(X,i) is an atomic Read-Modify-Write instruction that reads the value of memory location X, increments it by the value i, and returns the old value of X. It is used in the pseudo code shown below to implement a busy-wait lock. L is an unsigned integer shared variable initialized to 0. The value of 0 corresponds to lock being available, while any non-zero value corresponds to the lock being not available. AcquireLock(L){ while (Fetch_And_Add(L,1)) L = 1; } ReleaseLock(L){ L = 0;

1. fails as L can overflow
2. fails as L can take on a non-zero value when the lock is actually available
3. works correctly but may starve some processes
4. works correctly without starvation

✅ Correct Answer: 2

Suppose a fair six-sided die is rolled once. If the value on the die is 1, 2, or 3, the die is rolled a second time. What is the probability that the sum total of values that turn up is at least 6?

1. 10/2
2. 5/12
3. 2/3
4. 1/6

✅ Correct Answer: 2

An Internet Service Provider (ISP) has the following chunk of CIDR-based IP addresses available with it: 245.248.128.0/20. The ISP wants to give half of this chunk of addresses to Organization A, and a quarter to Organization B, while retaining the remaining with itself. Which of the following is a valid allocation of addresses to A and B?

1. 245.248.136.0/21 and 245.248.128.0/22
2. 245.248.128.0/21 and 245.248.128.0/22
3. 45.248.132.0/22 and 245.248.132.0/21
4. 45.248.136.0/24 and 245.248.132.0/21

✅ Correct Answer: 1

Suppose a circular queue of capacity (n âˆ’1) elements is implemented with an array of n elements. Assume that the insertion and deletion operations are carried out using REAR and FRONT as array index variables, respectively. Initially, REAR = FRONT = 0. The conditions to detect queue full and queue empty are

1. full: (REAR+1) mod n == FRONT empty: REAR == FRONT
2. full: (REAR+1) mod n == FRONT empty: (FRONT+1) mod n == REAR
3. full: REAR == FRONT empty: (REAR+1) mod n == FRONT
4. full: (FRONT+1) mod n == REAR empty: REAR == FRONT

✅ Correct Answer: 1

How many onto (or surjective) functions are there from an n-element (n â‰¥ 2) set to a 2-element set?

1. 2n
2. 2n - 1
3. 2n - 2
4. 2(2n - 2)

✅ Correct Answer: 3

A file system with 300 GByte disk uses a file descriptor with 8 direct block addresses, 1 indirect block address and 1 doubly indirect block address. The size of each disk block is 128 Bytes and the size of each disk block address is 8 Bytes. The maximum possible file size in this file system is

1. 3 KBytes
2. 35 KBytes
3. 280 KBytes
4. dependent on the size of the disk

✅ Correct Answer: 2

Suppose R1(A, B) and R2(C, D) are two relation schemas. Let r1 and r2 be the corresponding relation instances. B is a foreign key that refers to C in R2. If data in r1 and r2 satisfy referential integrity constraints, which of the following is ALWAYS TRUE?

1. Ï€B(r1) - Ï€C(r2) = Ã˜
2. Ï€C(r2) - Ï€B(r1) = Ã˜
3. Ï€B(r1) = Ï€C(r2)
4. Ï€B(r1) - Ï€C(r2) â‰ Ã˜

✅ Correct Answer: 1

Consider a source computer (S) transmitting a file of size 106 bits to a destination computer (D) over a network of two routers (R1 and R2) and three links (L1, L2 and L3). L1 connects S to R1; L2 connects R1 to R2; and L3 connects R2 to D. Let each link be of length 100 km. Assume signals travel over each link at a speed of 108 meters per second. Assume that the link bandwidth on each link is 1Mbps. Let the file be broken down into 1000 packets each of size 1000 bits. Find the total sum of transmission and propagation delays in transmitting the file from S to D?

1. 1005 ms
2. 1010 ms
3. 3000 ms
4. 3003 ms

✅ Correct Answer: 1

A computer has a 256 KByte, 4-way set associative, write back data cache with block size of 32 Bytes. The processor sends 32 bit addresses to the cache controller. Each cache tag directory entry contains, in addition to address tag, 2 valid bits, 1 modified bit and 1 replacement bit. The number of bits in the tag field of an address is

1. 11
2. 14
3. 16
4. 27

✅ Correct Answer: 3

A computer has a 256 KByte, 4-way set associative, write back data cache with block size of 32 Bytes. The processor sends 32 bit addresses to the cache controller. Each cache tag directory entry contains, in addition to address tag, 2 valid bits, 1 modified bit and 1 replacement bit. The size of the cache tag directory is

1. 60 Kbits
2. 136 Kbits
3. 40 Kbits
4. 32 Kbits

✅ Correct Answer: 1

The cost function for a product in a firm is given by 5q2, where q is the amount of production. The firm can sell the product at a market price of Rs. 50 per unit. The number of units to be produced by the firm such that the profit is maximized is

1. 5
2. 10
3. 15
4. 25

✅ Correct Answer: 1

Choose the most appropriate alternative from the options given below to complete the following sentence: Despite several “““““““““ the mission succeeded in its attempt to resolve the conflict.

1. attempts
2. setbacks
3. meetings
4. delegations

✅ Correct Answer: 2

Which one of the following options is the closest in meaning to the word given below? Mitigate

1. Diminish
2. Divulge
3. Dedicate
4. Denote

✅ Correct Answer: 1

Wanted Temporary, Part-time persons for the post of Field Interviewer to conduct personal interviews to collect and collate economic data. Requirements: High School-pass, must be available for Day, Evening and Saturday work. Transportation paid, expenses reimbursed. Which one of the following is the best inference from the above advertisement?

1. Gender-discriminatory
2. Xenophobic
3. Not designed to make the post attractive
4. Not gender-discriminatory

✅ Correct Answer: 4

A political party orders an arch for the entrance to the ground in which the annual convention is being held. The profile of the arch follows the equation y = 2x “ 0.1x2 where y is the height of the arch in meters. The maximum possible height of the arch is

1. 8 meters
2. 10 meters
3. 12 meters
4. 14 meters

✅ Correct Answer: 2

An automobile plant contracted to buy shock absorbers from two suppliers X and Y. X supplies 60% and Y supplies 40% of the shock absorbers. All shock absorbers are subjected to a quality test. The ones that pass the quality test are considered reliable. Of X's shock absorbers, 96% are reliable. Of Y's shock absorbers, 72% are reliable. The probability that a randomly chosen shock absorber, which is found to be reliable, is made by Y is

1. 0.288
2. 0.334
3. 0.667
4. 0.720

✅ Correct Answer: 2