# GATE – Sample Questions - MECH1

Discussion in 'Mechanical Students' started by Guest, Apr 5, 2007.

1. ### GuestGuest

No. Question
1

In PERT analysis a critical activity has
Options
A) maximum Float B) zero Float
C) maximum Cost D) minimum Cost
Your Answer (Not Answered)
Correct Answer B

2 Environment friendly refrigerant R134a is used in the new generation domestic refrigerators. Its chemical formula is
Options
A) CH C1 F2 B) C2 C13 F3
C) C2 C12 F4 D) C2 H2 F4
Your Answer (Not Answered)
Correct Answer D

3 A solid cylinder (surface 2) is located at the centre of a hollow sphere (surface 1). The diameter of the sphere is 1m, while the cylinder has a diameter and length of 0.5 m each. The radiation configuration factor F11 is
Options
A) 0.375 B) 0.625
C) 0.75 D) 1
Your Answer (Not Answered)
Correct Answer C

4 For a fluid flow through a divergent pipe of length L having inlet and outlet radii of R1 and R2 respectively and a constant flow rate of Q, assuming the velocity to be axial and uniform at any cross-section, the acceleration at the exit is
Options
A)
2Q(R1 - R2)
p LR23
B)
2Q2 (R1 - R2)
p LR23
C)
2Q2 (R1 - R2)
p2LR25
D)
2Q2 (R2 - R1)
p2LR25
Your Answer (Not Answered)
Correct Answer C

5 An incompressible fluid (kinematic viscosity, 7.4 x 10-7 m2/s, specific gravity, 0.88) is held between two parallel plates. If the top plate is moved with a velocity of 0.5 m/s while the bottom one is held stationary, the fluid attains a linear velocity profile in the gap of 0.5 mm between these plates; the shear stress in Pascals on the surface of top plate is
Options
A) 0.651 x 10-3 B) 0.651
C) 6.51 D) 0.651 x 103
Your Answer (Not Answered)
Correct Answer B

6 The tool of an NC machine has to move along a circular arc from (5,5) to (10,10) while performing an operation. The centre of the arc is at (10,5). Which one of the following NC tool path commands performs the above mentioned operation?
Options
A) N010 G02 X10 Y10 X5 Y5 R5 B) N010 G03 X10 Y10 X5 Y5 R5
C) N010 G01 X5 Y5 X10 Y10 R5 D) N010 G02 X5 Y5 X10 Y10 R5
Your Answer (Not Answered)
Correct Answer D

7 During a Morse test on a 4 cylinder engine, the following measurements of brake power were taken at constant speed.
All cylinders firing 3037 kW
Number 1 cylinder not firing 2102 kW
Number 2 cylinder not firing 2102 kW
Number 3 cylinder not firing 2100 kW
Number 4 cylinder not firing 2098 kW
The mechanical efficiency of the engine is
Options
A) 91.53% B) 85.07%
C) 81.07% D) 61.22%
Your Answer (Right Answer)

8 In terms of theoretical stress concentration factor (Kt) and fatigue stress concentration factor (Kf ), the notch sensitivity ‘q’ is expressed as
Options
A)
(Kf -1)
(Kt -1)
B)
(Kf -1)
(Kt +1)
C)
(Kt -1)
(Kf -1)
D)
(Kf +1)
(Kt +1)
Your Answer (Not Answered)
Correct Answer A

9 Starting from x0 = 1, one step of Newton-Raphson method in solving the equation x3 + 3x -7 = 0 gives the next value (x1) as
Options
A) x1 = 0.5 B)

x1= 1.406
C) x1= 1.5 D) x1 = 2
Your Answer (Not Answered)
Correct Answer C

10 A maintenance service facility has Poisson arrival rates, negative exponential service time and operates on a ‘first come first served’ queue discipline. Break downs occur on an average of 3 per day with a range of zero to eight. The maintenance crew can service an average of 6 machines per day with a range of zero to seven.
The mean waiting time for an item to be serviced would be
Options
A)
1
6
day B)
1
3
day
C) 1 day D) 3 days
Your Answer (Not Answered)
Correct Answer A

11 The S-N curve for steel becomes asymptotic nearly at

Options
A) 103 cycles B) 104 cycles
C) 106 cycles D) 109 cycles
Your Answer (Not Answered)
Correct Answer C

12 In a rolling process, sheet of 25 mm thickness is rolled to 20 mm thickness. Roll is of diameter 600 mm and it rotates at 100 rpm. The roll strip contact length will be
Options
A) 5 mm B) 39 mm
C) 78mm D) 120mm
Your Answer (Right Answer)

13 Water at 42°C is sprayed into a stream of air at atmospheric pressure, dry bulb temperature of 40°C and a wet bulb temperature of 20°C. The air leaving the spray humidifier is not saturated. Which of the following statements is true?
Options
A) Air gets cooled and humidified B) Air gets heated and humidified
C) Air gets heated and dehumidified D) Air gets cooled and dehumidified
Your Answer (Not Answered)
Correct Answer B

14 The angle between two unit-magnitude coplanar vectors P(0.866, 0.500,0) and Q(0.259, 0.966,0) will be
Options
A) 0° B) -30°
C) 45° D) 60°
Your Answer (Not Answered)
Correct Answer C

15

A lot has 10% defective items. Ten items are chosen randomly from this lot. The probability that exactly 2 of the chosen items are defective is
Options
A)

0.0036
B) 0.1937
C) 0.2234 D) 0.3874
Your Answer (Not Answered)
Correct Answer B

16 Two tools P and Q have signatures 5°-5°-6°-6°-8°-30°-0 and 5°-5°-7°-7°-8°-15°-0 (both ASA) respectively. They are used to turn components under the same machining conditions. If hp and hQ denote the peak-to-valley heights of surfaces produced by the tools P and Q, the ratio hp/hQ will be
Options
A) B)
C) D)
Your Answer (Right Answer)

17 For a typical sample of ambient air (at 35° C, 75% relative humidity and standard atmospheric pressure), the amount of moisture in kg per kg of dry air will be approximately
Options
A) 0.002 B) 0.027
C) 0.25 D) 0.75
Your Answer (Not Answered)
Correct Answer B

18 For a fluid flow through a divergent pipe of length L having inlet and outlet radii of R1 and R2 respectively and a constant flow rate of Q, assuming the velocity to be axial and uniform at any cross-section, the acceleration at the exit is
Options
A)
2Q(R1 - R2)
p LR23
B)
2Q2 (R1 - R2)
p LR23
C)
2Q2 (R1 - R2)
p2LR25
D)
2Q2 (R2 - R1)
p2LR25
Your Answer (Not Answered)
Correct Answer C

19 A mould has a downsprue whose length is 20 cm and the cross sectional area at the base of the downsprue is 1 cm2. The downsprue feeds a horizontal runner leading into the mould cavity of volume 1000 cm3 . The time required to fill the mould cavity will be
Options
A) 4.05 s B) 5.05 s
C) 6.05 s D) 7.25 s
Your Answer (Not Answered)
Correct Answer B

20

The values of a function f(x) are tabulated below
x f(x)
0 1
1 2
2 1
3 10
Using Newton,s forward difference formula, the cubic polynomial that can be fitted to the above data, is
Options
A) 2x3 + 7x2 - 6x + 2 B)

2x3 – 7x2 + 6x - 2
C)

x3 - 7x2 – 6x2 + 1
D)

2x3 - 7x2 + 6x + 1
Your Answer (Right Answer)