ISRO Scientist or Engineer Mechanical 2012

ISRO Scientist or Engineer Mechanical 2012 - Question 1

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A beam is having-a-triangular cross section with its neutral axis XX. The section modulus about XX is given by

A

$$\frac {bh^2} {6}$$

B

$$\frac {bh^2} {36}$$

C

$$\frac {bh^2} {24}$$

D

$$\frac {hb^2} {36}$$

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ISRO Scientist or Engineer Mechanical 2012 - Question 2

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A rectangular column is subjected to an eccentric load P at distance ‘e’ from centroidal Axis. The stress diagram at Cross- section will be

A

B

C

D

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ISRO Scientist or Engineer Mechanical 2012 - Question 3

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Two shafts A & B are made of same material. The radius of the shaft A is half that of shaft B. The power transmitted by the shaft A will be ___________ that of shaft B.

A

1/8 times

B

8 times

C

sixteen times

D

Twice

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ISRO Scientist or Engineer Mechanical 2012 - Question 4

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Four linear elastic springs are connected to mass ‘M’ as shown in Figure. The natural frequency of the system is

A

$$\frac{({\sqrt 4k/3m)}} {2\pi}$$

B

$$\frac{({\sqrt 4k/m)}} {2\pi}$$

C

$$\frac{({\sqrt k/4m)}} {2\pi}$$

D

$$\frac{({\sqrt 3k/4m)}} {2\pi}$$

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ISRO Scientist or Engineer Mechanical 2012 - Question 5

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Which bearing offers lowest friction

A

hydrostatic Bearing

B

Roller Bearing

C

Aero- static Bearing

D

Hydrodynamic Bearing

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ISRO Scientist or Engineer Mechanical 2012 - Question 6

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A circular disk of radius R rolls without slipping at a velocity V. The magnitude of the velocity at point P shown in the figure is

A

$$ \sqrt{3} V $$

B

$$ \frac {\sqrt {3}} {2} V $$

C

$$ \frac {V} {2} $$

D

$$ \sqrt {2} V $$

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ISRO Scientist or Engineer Mechanical 2012 - Question 7

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In the viscous damped vibration, the logarithmic decrement value over five cycles is found to be 8.11. What is viscous damping factor of vibratory system?

A

20%

B

25%

C

30%

D

15%

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ISRO Scientist or Engineer Mechanical 2012 - Question 8

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An elevator weighing 1000Kg attains an upward velocity of 4m/sec in two seconds with uniform acceleration. The tension (in N) in supporting cable will be $$(g = 9.8m/sec^2)$

A

1204 N

B

9800

C

2000 N

D

11800 N

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ISRO Scientist or Engineer Mechanical 2012 - Question 9

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A block weighting 981 N is resting on Horizontal surface. The co-efficient of friction between the block and horizontal surface is $$\mu = 0.2.$$ A vertical cable attached to block provides partial support as shown. A man can pull horizontally with a force of 100 N. What will be the tension (T)(in N)in the cable if the man is just able to move the block to the right?

A

176.2

B

196.0

C

481.0

D

981.0

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ISRO Scientist or Engineer Mechanical 2012 - Question 10

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A vehicle suspension system consists of a leaf spring and a damper. The stiffness of the leaf spring is 3.6 KN/m and damping constant of the damper is 400 Ns/m. If the mass is 50Kg, then the damping factor and damped natural frequency respectively are

A

0.471 and 1.19 Hz

B

0.471 and 7.48 Hz

C

0.666 and 1.35 Hz

D

0.666 and 8.50 Hz

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ISRO Scientist or Engineer Mechanical 2012 - Question 11

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A rotating disc of 1m diameter has two eccentric masses of 0.5 kg each at radi of 50mm and 60mm at angularposition of $$0^\circ$$ and $$150^\circ$$, respectively. A balancing mass of 0.1Kg is to be used to balance the rotor. Whatis the radial position of balancing mass?

A

50mm

B

120mm

C

150mm

D

280mm

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ISRO Scientist or Engineer Mechanical 2012 - Question 12

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Two mating spur gears have 40 & 120 teeth respectively. The pinion rotates at 1200 rpm and transmit torque of 20Nm. The torque transmitted by the gear is

A

6.6 Nm

B

20 Nm

C

40 Nm

D

60 Nm

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ISRO Scientist or Engineer Mechanical 2012 - Question 13

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The figure below shows a steel rod of $$25 mm^2$$ cross sectional area. It is loaded at four points, Kk, L, M, N. Assume E steel = 200 GPa. The total change in length of the rod due to loading is

A

$$1\mu m$$

B

$$-10\mu m $$

C

$$10\mu m $$

D

$$-20\mu m $$

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ISRO Scientist or Engineer Mechanical 2012 - Question 14

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Planetary gear is in contact with the fixed gear as shown in the figure. The number of rotations made by the planetary gear for one rotation of the arm is

A

3

B

4

C

1

D

$$\frac{1}{3}$$

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ISRO Scientist or Engineer Mechanical 2012 - Question 15

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The Mohr circle reduces to a point when the body is subjected to

A

pure shear

B

uniaxial shear only

C

equal axial stress on two mutually perpendicular planes and the planes being free of shear

D

equal and opposite axial stress on two mutually perpendicular planes and the planes being free of shear

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ISRO Scientist or Engineer Mechanical 2012 - Question 16

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Shear stress distribution for a rectangular beam subjected to transverse loading is

A

a

B

b

C

c

D

d

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ISRO Scientist or Engineer Mechanical 2012 - Question 17

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Area moment of inertia for the quadrant shown below is

A

$$ \frac {\pi r^4} {2}$$

B

$$ \frac {\pi r^4} {4}$$

C

$$ \frac {\pi r^4} {8}$$

D

$$ \frac {\pi r^4} {16}$$

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ISRO Scientist or Engineer Mechanical 2012 - Question 18

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A column of length ‘L’is fixed at bottom end and hinged at the other end. This column is restrained from lateral displacement at $${\frac{1}{3}^{rd}} $$height. The buckling load is given by

A

$$\frac {9\pi^2 EI}{(4L^2)}$$

B

$$ \frac {4\pi^2 EI}{L^2} $$

C

$$\frac {4\pi^2 EI}{(9L^2)}$$

D

$$\frac {\pi^2 EI}{L^2} $$

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ISRO Scientist or Engineer Mechanical 2012 - Question 19

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A shaft has two heavy rotors mounted on it. The transverse natural frequency considering each rotor separately is 100 hz & 200 hz respectively. The lowest critical speed is

A

13000 rpm

B

5367 rpm

C

6450 rpm

D

9343 rpm

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ISRO Scientist or Engineer Mechanical 2012 - Question 20

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A mass ‘M' is suspended from a ceiling through a string of length ‘L’. This mass moves in a circle of horizontal radius ‘r’ at constant speed such that it is a conical pendulum. The tension in the string will be

A

$$ \frac {mgL} {(2\sqrt{L^2 - r^2})}$$

B

$$ \frac {mgL} {\sqrt{L^2 }} $$

C

$$ \frac {mgL} {\sqrt{r^2 }} $$

D

$$ \frac {mgL} {(\sqrt{L^2 - r^2})}$$

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ISRO Scientist or Engineer Mechanical 2012 - Question 21

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The stress in the rod AB in the pin jointed truss ABCD is

A

$$ \frac {2P}{\pi d^2} $$

B

$$ \frac {4P}{\pi d^2} $$

C

0

D

$$ \frac {P}{2 \pi d^2} $$

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ISRO Scientist or Engineer Mechanical 2012 - Question 22

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The number of degrees of freedom for the following mechanism is

A

0

B

1

C

2

D

4

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ISRO Scientist or Engineer Mechanical 2012 - Question 23

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A plate is held by a chain AB through hinge joints. The plate is pulled with a force T as shown in figure. The tension in the chain is given by

A

$$ \left(\frac {\sqrt{3}} {2}\right) T $$

B

$$ \left(\frac {\sqrt 2} {3}\right) T $$

C

$$ \frac {T} {2} $$

D

$$ 3 \sqrt 2 T $$

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ISRO Scientist or Engineer Mechanical 2012 - Question 24

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In a turn buckle joint, both mating rods will have

A

Right hand threads

B

Left hand threads

C

Right hand and left hand threads

D

Multiple threads

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ISRO Scientist or Engineer Mechanical 2012 - Question 25

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In flat belt drive, the belt can be subjected to a maximum tension (T) and centrifugal tension $$(T_c)$$. The condition of transmission of maximum power is given by

A

$$ T = T_c $$

B

$$ T = 2T_c $$

C

$$ T = 3T_c $$

D

$$ T = \sqrt 3 T_c $$

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ISRO Scientist or Engineer Mechanical 2012 - Question 26

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The diameter of a soap bubble which has an inside pressure of $$2.5 N/m^2$$ over the atmospheric pressure and a surface tension of 0.0125 N/m is

A

40 mm

B

4 mm

C

16 mm

D

60 mm

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ISRO Scientist or Engineer Mechanical 2012 - Question 27

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Find the loss of head dueto friction in a smooth pipe of rectangular cross section of $$1m \times 0.5m$$ and 10m long. Velocity of flow is 10 m/s and the friction coefficient is 0.01962.

A

4 m

B

6 m

C

8 m

D

10 m

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ISRO Scientist or Engineer Mechanical 2012 - Question 28

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Whena supersonic flow is admitted into a convergent, the flow will

A

Accelerate

B

Decelerate

C

No change

D

None of the above

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ISRO Scientist or Engineer Mechanical 2012 - Question 29

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Which configuration measures the stagnation pressure?

A

a

B

b

C

c

D

d

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ISRO Scientist or Engineer Mechanical 2012 - Question 30

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The maximum lift in a centrifugal pump would be close to ‘X’ if the pump is handling cold water $$(25^\circ C)$$ from an open tank at sea level with no friction and turbulence loses, where ‘X’ is equal to

A

10 m

B

1.03 m

C

100 m

D

30 m

View Solution

ISRO Scientist or Engineer Mechanical 2012 - Question 31

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Both pressure and velocity of steam drops in the moving blades of

A

Impulse turbine

B

Velocity compounded impulse turbine

C

Reaction turbine

D

Pressure compounded impulse turbine

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ISRO Scientist or Engineer Mechanical 2012 - Question 32

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A model of a golf ball is to be studied to determine the effects of the dimples. A sphere 10 times larger in diameter than an actual golf ball is used in the wind tunnel study. What speed should be selected for the model to simulate a prototype speed of50 m/s?

A

0.2 m/s

B

5 m/s

C

50 m/s

D

10 m/s

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ISRO Scientist or Engineer Mechanical 2012 - Question 33

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The sound of explosion on a ship located 10km away from the beach was heard 28.6 seconds after the explosion was seen. Estimate the temperatureofair at that time.

A

$$ 31^\circ C $$

B

$$ 31 K $$

C

$$ 26.2^\circ C $$

D

$$ 288.5K $$

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ISRO Scientist or Engineer Mechanical 2012 - Question 34

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A spherical balloon is filled with helium at sea level. Helium and balloon material together weigh 500 N.If the net upward lift force on the balloon is also 500 N, whatis the diameter of the balloon?

A

5.42m

B

6.78m

C

3.43m

D

2.34m

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ISRO Scientist or Engineer Mechanical 2012 - Question 35

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Air at $$ 20^\circ C $$ and $$ 10^5 $$ Pa enters the bottom of an $$ 85^\circ $$ conical flow meter duct at a mass flow rate of 0.3 kg/s, as shown in the figure. It supports the centered conical body by steady annular flow around the cone and exits at the same velocity as it enters. Estimate the weight of the body in Newtons

A

2.5N

B

1N

C

3.5N

D

4N

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ISRO Scientist or Engineer Mechanical 2012 - Question 36

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A jet of water issues from a nozzle with a velocity 20 m/s on a flat plate moving away from it at 10 m/s. The cross sectional area of the jet is $$ 0.01 m^2$$ and the density of water $$= 1000  kg/m^3.$$ The force developed on the plate is

A

1000 N

B

100 N

C

10 N

D

2000 N

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ISRO Scientist or Engineer Mechanical 2012 - Question 37

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The laminar boundary layer thickness varies as

A

$$\frac {1} {\sqrt x}$$

B

$$ x^{\frac{1}{7}} $$

C

$$ x^{\frac{1}{2}} $$

D

$$ x^{\frac{6}{7}} $$

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ISRO Scientist or Engineer Mechanical 2012 - Question 38

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An increase in pressure of a liquid from 7.5 MPa to 15 MPa results into 0.2 percent decrease in its volume. The Coefficient of compressibility of the liquid in $$ m^2/N $$ is

A

$$ 0.267 \times 10^{-9} $$

B

$$ 2.67 \times 10^{-9} $$

C

$$ 1 \times 10^{-9} $$

D

None of the above

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ISRO Scientist or Engineer Mechanical 2012 - Question 39

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A reservoir of capacity $$0.01m^3$$ is completely filled with a fluid of coefficient of compressibility $$0.75 x 10^{-9} m^2/N$$. The amount of fluid that will spill over $$(in m^3)$$,if pressure in the reservoir is reduced by $$ 2 \times 10^7 N/m^2 $$ is

A

$$ 1 \times 10^{-4} $$

B

$$ 1.5 \times 10^{-4} $$

C

$$ 0.15 \times 10^{-4} $$

D

None of the above

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ISRO Scientist or Engineer Mechanical 2012 - Question 40

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The extent of pressure produced due to water hammer depends on

A

Velocity of flow of fluid in the pipe

B

length of the pipe

C

time taken to close the valve; gtadual or quick closure of the valve

D

All the above

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ISRO Scientist or Engineer Mechanical 2012 - Question 41

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Rank of the matrix
$$ A = \begin{bmatrix}1 & 1 & 2 \\1 & 2 & 3 \\ 0 & -1 & 1 \end{bmatrix} $$ is

A

0

B

1

C

2

D

3

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ISRO Scientist or Engineer Mechanical 2012 - Question 42

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The value of $$t$$ for which $$A + tB$$ is perpendicular to $$C$$ where $$A = i + 2j + 3k, B = -i + 2j + k$$ and $$C = 3i + j$$

A

5

B

4

C

12

D

0

View Solution

ISRO Scientist or Engineer Mechanical 2012 - Question 43

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$$ \overline{A} \times \overline{B} $$ is a vector

A

Parallel to $$\overline{A},$$ but perpendicular to $$\overline{B}$$

B

Parallel to $$\overline{B},$$ but perpendicular to $$\overline{A}$$

C

Perpendicular to both $$\overline{A} \& \overline{B}$$

D

Parallel to both $$\overline{A} \& \overline{B}$$

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ISRO Scientist or Engineer Mechanical 2012 - Question 44

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The equation of the plane through the line $$ \frac {x - 1}{3} = \frac {y - 4}{2} = \frac {z - 4}{-2} $$ and parallel to the line $$ \frac {x + 1}{2} = \frac {y - 1}{-4} = \frac {z + 2}{1} $$ is

A

$$3x + 2y - 2z = 101$$

B

$$2x - 4y + z = 98$$

C

$$6x + 7y + 16z = 98$$

D

$$6x - 8y - 2z = 101$$

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ISRO Scientist or Engineer Mechanical 2012 - Question 45

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Let $$E$$ and $$F$$ be any two events with $$4 P(E \cup F) = 0.8, P(E) = 0.4$$ and $$P (E/F) = 0.3$$.Then $$(F)$$ is .

A

$$\frac {3} {7} $$

B

$$\frac {4} {7} $$

C

$$\frac {3} {5} $$

D

$$\frac {2} {5} $$

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ISRO Scientist or Engineer Mechanical 2012 - Question 46

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The approximate value of y(0.1) from $$\frac {dy} {dx} = x^2 y-1, y(0) = 1$$ is

A

0.900

B

1.001

C

0.802

D

0.994

View Solution

ISRO Scientist or Engineer Mechanical 2012 - Question 47

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1+ i is equivalent to

A

$$ \sqrt 2e^\frac{-i \pi} {4} $$

B

$$ \sqrt 2e^\frac{i \pi} {4} $$

C

$$ 2e^\frac{-i \pi} {4} $$

D

$$ 2e^\frac{i \pi} {4} $$

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ISRO Scientist or Engineer Mechanical 2012 - Question 48

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In a class of 45 students, the mean mark of 25 girls is 32 and the mean mark of 20 boys is 27.5. What is the class mean?

A

32

B

27.5

C

29.75

D

30

View Solution

ISRO Scientist or Engineer Mechanical 2012 - Question 49

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If $$ L \left\{ f(t) \right\} = F (s),$$ then the value of $$ L \left\{ e^{-at} f(t) \right\} $$ is

A

$$ F (s - a) $$

B

$$ F (s + a) $$

C

$$ F (s) $$

D

$$ F (e^as) $$

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ISRO Scientist or Engineer Mechanical 2012 - Question 50

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The probability that A happens is $$\frac{1}{3}$$. The odds against happening of A are

A

$$2 : 1$$

B

$$3 : 2$$

C

$$1 : 2$$

D

$$2 : 3$$

View Solution

ISRO Scientist or Engineer Mechanical 2012 - Question 51

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Draft on pattern for casting is provided for

A

Shrinkage allowance

B

Identification

C

Taper to facilitate removal from mould

D

Machining allowance

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ISRO Scientist or Engineer Mechanical 2012 - Question 52

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Welding spatter is

A

Welding defect

B

Flux

C

Electrode Coating

D

Welding technique

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ISRO Scientist or Engineer Mechanical 2012 - Question 53

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Which of the following statementsis false about annealing? Annealing is done to

A

Harden Steel slightly

B

Relieve Stress |

C

Soften metal

D

Permit further cold working

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ISRO Scientist or Engineer Mechanical 2012 - Question 54

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The property of corrosion resistance of chromium Stainless Steel is due to

A

Predominant nature of Cr present in stainless steel

B

The formation of thin film of oxygen & moisture absorbed from the atmosphere |

C

The formation of a thin film of $$ Cr_2O_3 $$ on the surface ofsteel

D

The inherent property of Cr to resist corrosion

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ISRO Scientist or Engineer Mechanical 2012 - Question 55

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Hot working operation is carried out at

A

Re-crystallization temperature

B

Near plastic stage temperature

C

Below re-crystallization

D

Above re-crystallization

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ISRO Scientist or Engineer Mechanical 2012 - Question 56

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The engineering and true strains for a bar which is doubled in length during tension test are

A

$$ e = 1.0, \epsilon = 0.693 $$

B

$$ e = 2, \epsilon = 1 $$

C

$$ e = \frac{1}{2}, \epsilon = \frac{1}{2} $$

D

Noneof the above

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ISRO Scientist or Engineer Mechanical 2012 - Question 57

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The purpose of adding wood flour to the moulding sand is to improve

A

Green strength

B

Hot Strength

C

Collapsibility

D

Permeability

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ISRO Scientist or Engineer Mechanical 2012 - Question 58

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Stretch forming is a process in which

A

All deformations occur in the direction of stretch

B

All forces are applied in the direction of stretch

C

Advantage is taken of plastic state indicated due to stretch

D

No dies are used

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ISRO Scientist or Engineer Mechanical 2012 - Question 59

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In which type of welding, a pool of molten metal is used?

A

Submerged arc welding

B

Electro slag welding

C

TIG welding

D

MIG welding

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ISRO Scientist or Engineer Mechanical 2012 - Question 60

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A mild steel block of width 40mm is being milled using a straight slab cutter 70mm diameter with 30 teeth. If the cutter rotates at 40 rpm, and depth of cut is 2mm, what is the value of maximum uncut chip thickness when the table feed is 20 mm/min?

A

0.00263mm

B

0.00363mm

C

0.00463mm

D

0.00563mm

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ISRO Scientist or Engineer Mechanical 2012 - Question 61

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Match the list I with list II and select the correct answer from the codes given in the lists below:

A

A-1, B-2, C-3, D-4

B

A-4, B-3, C-1, D-2

C

A-4, B-3, C-2, D-1

D

A-3, B-4, C-1, D-2

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ISRO Scientist or Engineer Mechanical 2012 - Question 62

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A shaft has a dimension $$ \phi 35^{\frac {-0.009} {-0.025}},$$ the respective values of fundamental deviation and tolerance are

A

- 0.025, 0.008

B

- 0.0025, 0.016

C

- 0.009, 0.008

D

- 0.009, 0.016

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ISRO Scientist or Engineer Mechanical 2012 - Question 63

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When a material sustains steady loads for long periods of time, the material may continue to deform until they may tend to fracture under the same load. This phenomenon is known as

A

Creep

B

Fatigue

C

Impact

D

Malleability

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ISRO Scientist or Engineer Mechanical 2012 - Question 64

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Which one of the following is a wrong statement?

A

In low carbon steels, phosphorus is added to raise its yield point

B

Lining of open hearth furnace controls impurities in steel

C

Blast furnace uses coke as fuel

D

Manganese is added in blast furnace for better fluidity

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ISRO Scientist or Engineer Mechanical 2012 - Question 65

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The most popular and standard typeforall purpose tool steels is 18:4:1 High Speed Steel (H.S.S.), which contains.

A

18% chromium, 4% tungsten and 1% vanadium

B

18% tungsten, 4% vanadium and 1% chromium

C

18% tungsten, 4% chromium and 1% vanadium

D

18% vanadium, 4% chromium and 1% tungsten

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ISRO Scientist or Engineer Mechanical 2012 - Question 66

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Water is boiled at $$1\times10^5 $$ Pa pressure in a coffee maker equipped with an immersion-type electric_heating-element. The coffee maker initially contains 1 kg of water. Once boiling started, it is observed that half of the water in the coffee maker evaporated in 18 minutes. If the heat loss from the coffee maker is negligible, the power rating of the heating element is

A

0.90 kW

B

1.52 kW

C

1.05 kW

D

1.24 kW

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ISRO Scientist or Engineer Mechanical 2012 - Question 67

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An adiabatic heat exchanger is used to heat cold water at $$15^\circ C$$ entering at a rate of 5 kg/s by hotair at $$90^\circ C$$ entering also at rate of 5 kg/s. If the exit temperatureof hot air is $$20^\circ C$$, the exit temperature of cold water is

A

$$27^\circ C$$

B

$$32^\circ C$$

C

$$85^\circ C$$

D

$$90^\circ C$$

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ISRO Scientist or Engineer Mechanical 2012 - Question 68

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Logmean area ‘A’ can be given as.

A

$$ \frac {\log A2 - \log A1}{A2 - A1} $$

B

$$ \frac {A2 - A1} {\log A2 - \log A1} $$

C

$$ \frac {\log A2 - \log A1}{\log \left(\frac {A2}{A1}\right)} $$

D

None

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ISRO Scientist or Engineer Mechanical 2012 - Question 69

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Nusselt number is the ratio of

A

Convective and Conductive resistances

B

Conductive and Convective resistances

C

Wall heat transfer rate to mass heat flow rate

D

Kinetic viscosity to thermal diffusivity

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ISRO Scientist or Engineer Mechanical 2012 - Question 70

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Zeroth law of thermodynamics is not valid for the following

A

50 mlof water at $$ 25^\circ C$$ is mixed with 150 ml of water at $$ 25^\circ C$$

B

500 ml of milk at $$ 15^\circ C$$ is mixed with 100 ml of water at $$ 15^\circ C$$

C

5 kg of wet steam at $$ 100^\circ C$$ is mixed with 50 kg of dry and saturated steam

D

10 mlof waterat $$ 20^\circ C$$ is mixed with 10 ml of sulphuric acid at $$ 20^\circ C$$

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ISRO Scientist or Engineer Mechanical 2012 - Question 71

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When air expands from initial pressure $$P_1$$ and volume $$V_1$$ tofinal volume $$5V_1$$ following the law $$PV^n = C$$

A

greater the value of n, greater the work obtained

B

smaller the value of n, smaller the work obtained

C

for n = 0, the work obtained is the greatest

D

for n = 1.4,the work obtained is the greatest

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ISRO Scientist or Engineer Mechanical 2012 - Question 72

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Air is compressed to half the volume at constant pressure, then the change in entropy

A

increase

B

decrease

C

does not change

D

not predictable

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ISRO Scientist or Engineer Mechanical 2012 - Question 73

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A cycle is shown below on P-V diagram

This cycle is represented in T-S diagram by

A

B

C

D

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ISRO Scientist or Engineer Mechanical 2012 - Question 74

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If 2 bar of air at $$27^\circ C$$ is heated to $$177^\circ C$$ at constant volume, the pressure will be

A

6.56 bar

B

3 bar

C

9 bar

D

13.11 bar

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ISRO Scientist or Engineer Mechanical 2012 - Question 75

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A friction less heat engine can be 100 percent efficient only if its exhaust temperature is

A

Equal to its input temperature

B

less than input temperature

C

0 K

D

$$ 0^\circ C$$

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ISRO Scientist or Engineer Mechanical 2012 - Question 76

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An ideal engine absorbs heat at $$ 127^\circ C$$ andrejects at $$ 77^\circ C$$. Theefficiency is

A

13%

B

39%

C

50%

D

40%

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ISRO Scientist or Engineer Mechanical 2012 - Question 77

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A Francis turbine running at 200 rpm develops a power of 5000 kW under a head of 25m.
The power output under a head of 100 m will be

A

20,000 kW

B

30,000 kW

C

40,000 kW

D

50,000 kW

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ISRO Scientist or Engineer Mechanical 2012 - Question 78

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Steam expands in a turbine from 40 bar, $$ 500^\circ C$$ to 0.10 bar isentropically. Assuming ideal conditions, given enthalpy drop 1198.8 kJ/kg, nozzle angle $$16^\cir$$ and N as 300 rpm. Mean diameter of the wheel,if the turbine were of simple impulse stage, will be

A

3.73 m

B

4.73 m

C

5.63 m

D

4.96 m

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ISRO Scientist or Engineer Mechanical 2012 - Question 79

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A refrigerator removes heat froma refrigerated space at $$0-5^\circ C$$ at a rate of 0.35 kJ/s and rejects it to an environment at $$20^\circ C$$. The minimum required power input is

A

30W

B

33W

C

56W

D

124W

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ISRO Scientist or Engineer Mechanical 2012 - Question 80

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For the same compression ratio, the thermodynamic cycles in the order of decreasing efficiencies are

A

Dual, Diesel, Otto

B

Dual, Otto, Diesel

C

Diesel, Dual, Otto

D

Otto, Dual, Diesel

View Solution