### ISRO Mechanical Previous Year Paper (2006):

**Ques.** In nodular iron, graphite is in the form of

(a) Cementite

(b) Free carbon

(c) Flakes

(d) Spheroids

**Ques.** Hardness of steel depends on

(a) Amount of carbon it contains

(b) The shape and distribution of the carbides in iron

(c) Method of fabrication

(d) Contents of alloying elements

**Ques.** Too high welding current in arc welding would result in

(a) Excessive spatter, under cutting along edges, irregular deposits, wasted electrodes

(b) Excessive piling up of weld metal, poor penetration, wasted electrodes

(c) Too small bead, weak weld and wasted electrodes

(d) Excessive piling up of weld metal, overlapping without penetration of edges, wasted electrodes

**Ques.** Which of the following processes would produce strongest components?

(a) Hot rolling

(b) Extrusion

(c) Cold rolling

(d) Forging

**Ques.** Which of the following has maximum hardness

(a) Austenite

(b) Pearlite

(c) Troostite

(d) Martensite

**Ques.** The main advantage of line organization is its

(a) Effective command and control

(b) Defined responsibilities at all levels

(c) Rigid discipline in the organization

(d) All of the above

**Ques.** The mathematical technique for finding the best use of limited resources in an optimum manner is known as

(a) Operation research

(b) Linear programming

(c) Network analysis

(d) Queuing theory

**Related:** ISRO Electronics Previous Year Paper

**Ques.** Which of the following errors are generally distributed in accordance with the Gaussian distribution

(a) Controllable errors

(b) Calibration errors

(c) Avoidable errors

(d) Random errors

**Ques.** Hydraulic testing of boilers is done at pressures

(a) Below and above atmosphere

(b) Slightly above atmospheric pressure

(c) At half the working pressure of boiler

(d) At 1.5 to 2 times the working pressure

**Ques.** Gantry girders are invariably designed to resist

(a) Transverse loads only

(b) Lateral loads only

(c) Transverse and lateral loads

(d) Transverse, lateral and axial load

**Download Complete Paper in PDF:** https://www.examsegg.com/downloads/isro-mechanical-engineering-paper-2006.pdf

### ISRO 2007 Question Paper Mechanical:

**Ques.** Only rocket engines can be propelled to space because

(a) They can generate very high thrust

(b) They have high propulsion efficiency

(c) These engines can work on several fuels

(d) They are not air-breathing engines

**Ques.** The universal gas constant of a gas is the product of molecular weight of the gas and

(a) Gas constant

(b) Specific heat at constant pressure

(c) Specific heat at constant volume

(d) None of the above

**Ques.** A spherical shaped vessel of 1.4 m outer diameter is 90 mm thick. Find the rate of heat leakage, if the temperature difference between the inner and outer surfaces is 220°C. Thermal conductivity of the material of the sphere is 0.083 W/m K.

(a) 0.2 kW

(b) 0.5 kW

(c) 1.088 kW

(d) 1.6 kW

**Ques.** With rise in temperature thermal conductivity of air

(a) Increases

(b) Decreases

(c) Remains constant

(d) May increase or decrease depending on temperature

**Ques.** Chances of occurrence of cavitation are high if the

(a) Local pressure becomes very high

(b) Local pressure falls below the vapour pressure

(c) Thoma cavitation parameter exceeds a certain limit

(d) Local temperature becomes low

**Ques.** A liquid compressed in cylinder has a volume of 0.04 m^{3} at 50 kg/cm^{2} and a volume of 0.039 m^{3} at 150 kg/cm^{2}. The bulk modulus of liquid is

(a) 400 kg/cm^{2}

(b) 4000 kg/cm^{2
}(c) 40 x 10^{5} kg/cm^{2}

(d) 40 x 10^{6} kg/cm^{2}

**Ques.** The buoyancy depends on

(a) Mass of liquid displaced

(b) Viscosity of the liquid

(c) Pressure of the liquid displaced

(d) Depth of immersion

**Related:** Mechanical Engg Paper for GATE

**Ques.** A fluid jet discharging from a 100 mm diameter orifice has a diameter of 80 mm at its vena contracta. The coefficient of contraction is

(a) 0.8

(b)1.25

(c) 0.2

(d) 0.64

**Ques.** A centrifugal pump with peripheral speed ‘V was selected for a total lift of 100 m. Actually pump was to be operated for a total lift of 400 m. The peripheral speed should actually be (other conditions remaining same)

(a) 2V

(b) 4V

(c) 8V

(d) 1V

**Ques.** A pipeline connecting two reservoirs has its diameter reduced by 20% due to deposition of chemicals. For a given head difference in the reservoirs with unaltered friction factor, this would cause a reduction in discharge of

(a) 42.8%

(b) 20%

(c) 17.8%

(d) 10.6%

**Download PDF:** https://www.examsegg.com/downloads/isro-mechanical-engineering-paper-2007.pdf

### ISRO 2008 Paper Mechanical Engineering:

**Ques.** The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to -150°C will

(a) Increase

(b) Decrease

(c) Remain same

(d) First increase and then decrease

**Ques.** “Troosite” is obtained when

(a) Quenching steel during transformation

(b) A fully hardened steel is finally drawn at about 677 ° C

(c) Steel is rapidly quenched in oil

(d) When alloy steels are rapidly quenched in water

**Ques.** Induction hardening is the process of

(a) Hardening the core

(b) Uniform hardening

(c) Selective hardening

(d) Hardening surface for wear resistance

**Ques.** Heavy water is used in atomic power plants as

(a) Fuel

(b) Source of energy

(c) Lubricant

(d) Moderator

**Ques.** Which one is not the purpose of heat treatment of steels?

(a) Changing the composition of steel on the surface

(b) Changing the percentage of carbon and Si in the bulk

(c) Increasing or decreasing the grain size

(d) Removing undesirable residual stresses

**Ques.** A cold chisel is made of

(a) Mild steel

(b) Cast iron

(c) H.S.S.

(d) High carbon

Related: Civil Service ME Syllabus

**Ques.** A body which is permanently deformed is said to have undergone

(a) Elastic deformation

(b) Limit of elastic deformation

(c) Plastic deformation

(d) Uniform deformation

**Ques.** The defect responsible for the phenomena of slip, by which most metals deform plastically, is known as

(a) Fracture

(b) Twinning

(c) Dislocation

(d) Strain hardening

**Ques.** For traction applications, the type of motor best suited is

(a) Induction motor

(b) Synchronous motor

(c) DC shunt motor

(d) DC series motor

**Ques.** On loading a ductile material in excess of a certain value, gradual increase in elongation occurs with time. Such phenomenon is known as

(a) Creep

(b) Fatigue

(c) Stress concentration

(d) None of the above

PDF Link: https://www.examsegg.com/downloads/isro-mechanical-engineering-paper-2008.pdf

### ISRO Mechanical Paper 2009:

**Ques.** A hydraulic press has a ram of 15 cm diameter and plunger of 1.5 cm. It is required to lift a mass of 1000kg. The force required on plunger is nearly equal to

(a) 100 N

(b) 1000 N

(c) 10000 N

(d) 10 N

**Ques.** If the stream function is given by * ^{y}V= *3xy, then the velocity at a point (2,3) will be

(a) 7.2 limit

(b) 18 unit

(c) 10.82 unit

(d) 54 unit

**Ques.** The correct sequence of the centrifugal pump components through which the fluid flows is

(a) Impeller, Suction pipe, Foot valve and strainer, Delivery pipe

(b) Foot valve and strainer. Suction pipe. Impeller, Delivery pipe

(c) Impeller, Suction pipe. Delivery pipe, Foot valve and strainer

(d) Suction pipe. Delivery pipe. Impeller, Foot valve and strainer

**Ques.** The relation pV’ = constant, where / is the ratio of the specific heats of ideal gas, is applicable to

(a) Any adiabatic process

(b) Only reversible adiabatic process

(c) Only irreversible adiabatic process

(d) Only isothermal process

**Ques.** Across a normal shock

(a) static pressure and the static temperature rise

(b) entropy remains constant

(c) velocity and static pressure decrease

(d) density and temperature decrease

**Related:** Career Guide for Mechanical Engineers

**Ques.** A necessary precaution in selection of pumps for parallel operations is that

(a) H-Q characteristics of both should be identical

(b) Both pumps should be centrifugal type

(c) Both pumps should be identical

(d) There should not be change from positive to negative slope in H-Q curve

**Ques.** A metallic cube of side 10 cm, density 6.8 gm/cc is floating in liquid mercury *(density 13.6gm/c(c), *with 5 cm height of cube exposed above the mercury level. Water *(density 1 gm/c(c) *is filled over this, to submerge the cube fully. The new height of cube exposed above mercury level is

(a) 4.6 cm (b) 5.4 cm

(c) 5.0 cm

(d) 5.8 cm

**Ques.** The pressure drop for a relatively low Reynolds number flow in a 600 mm, 30 m long pipeline is 70kPa. What is the wall shear stress?

(a) 0 Pa

(b) 1400 Pa

(c) 700 Pa

(d) 350 Pa

**Ques.** At the eye tip of a centrifugal impeller, blade velocity is 200 m/s while the uniform axial velocity at the inlet is 150 m/s. If the sonic velocity is 300 m/s, then the inlet Mach number of the flow will be

(a) 0.75

(b) 0.66

(c) 0.90

(d) 0.82

**Ques.** A bucket of water is hanging from a spring balance. An iron piece is suspended into water without touching sides of bucket from another support. The spring balance reading will

(a) Remain same

(b) Decrease

(c) Increase

(d) Increase/decrease depending on depth of immersion

**Download Full Paper:** https://www.examsegg.com/downloads/isro-mechanical-engineering-paper-2009.pdf

### ISRO Scientist Engineer ME Question Paper 2010

**Ques.** A wire is plastically deformed bent by supplying a force of 40 N over a distance of 0.8 m. (The force moves in the direction in which the distance is measure(d). If the wire has a mass of 0.2 kg and a specific heat of 0.5 kJ/kg.°C estimate the maximum increase in the average temperature of the wire

(a) 0.03°C

(b) 0.3°C

(c) 3°C

(d) 30°C

**Ques.** Two rods one of length L and the other of length 2L are made of the same material and have the same diameter. The two ends of the longer diameter. The two ends of the longer rod are maintained at 100°C. One end of the shorter rod is maintained at 100° C while the other end is insulated. Both the rods are exposed to the same environment at 40°C. The temperature at the insulated end of the shorter rod is measured to be 55 ° C. The temperature at the midpoint of the longer rod would be

(a) 40°C

(b) 50°C

(c) 55°C

(d) 100°C

**Ques.** A sphere, a cube and a disc all of the same material, quality and volume are heated to 900 K and left in air. Which of these will have the lowest rate of cooling

(a) Cube

(b) Disc

(c) Sphere

(d) All will have the same rate of cooling

Related: GATE Entrance Exam ME Syllabus

**Ques.** The temperature of sun can be measured using a

(a) Standards thermometer

(b) Radiation pyrometer

(c) Platinum resistance thermometer

(d) Mercury thermometer

**Ques.** A car moving with uniform acceleration covers 450 m in a 5 second interval, and covers 700 m in the next 5 second interval. The acceleration of the car is

(a) 7 m/s^{2
}(b) 50m/s^{2
}(c) 25 m/s^{2
}(d) 10 m/s^{2}

**Ques.** Two metallic blocks having masses in the ratio 2: 3 are made to slide down a friction less inclined plane starting initially from rest position. When these blocks reach the bottom of the inclined plane, they will have their kinetic energies in the ratio

(a) 2:3

(b) 3:5

(c) 3:2

(d) 7:4

**Ques.** For solid shaft subjected to a torque of 18000 Nm having a permissible shear stress of 60N/mm^{2}, the diameter of shaft is

(a) 115mm

(b) 121mm

(c) 149mm

(d) 108mm

**Ques.** Shear force is

(a) Rate of change of loading

(b) Sum of bending moments

(c) Rate of change of bending moment

(d) None of the above

**Related:** Air Force Mechanical Engg Jobs

**Ques.** Maximum shear stress in Mohr’s circle is equal to

(a) Radius of circle

(b) Diameter of circle

(c) Center of circle from y-axis

(d) Chord of circle

**Ques.** Maximum deflection in cantilever due to pure bending moment M at its end is

(a) M1^{2}/2E1

(b) M1^{2}/3E1

(c) M1^{2}/4E1

(d) M1^{2}/6EI

**PDF:** https://www.examsegg.com/downloads/isro-mechanical-engineering-paper-2010.pdf

### 2011 Mechanical Engineering Paper ISRO:

**Ques.** A gas is so expanded in a cylinder that its temperature remains constant. The resulting variation of pressure vs. volume is

(a) A parabola

(b) A hyperbola

(c) A straight line through origin

(d) None of these

**Ques.** According to first law of thermodynamics

(a) Mass and energy are mutually convertible

(b) Heat and work are mutually convertible

(c) Heat flows from hot substance to cold

(d) Carnot engine is most efficient substance

**Ques.** If the discharge of a centrifugal pump is throttled then its suction lift

(a) Decreases

(b) First increases and then decreases

(c) Remains unchanged

(d) Increases

**Ques.** A manometer measures the pressure differential between two locations of a pipe carrying water. If the manometric liquid is mercury (specific gravity 13.6) and the manometer showed a level difference of 20 cm, then the pressure head difference of water between the two tapings will be

(a) 1.26 m

(b) 2.72 m

(c) 1.36 m

(d) 2.52 m

**Ques.** Flow takes place at Reynolds Number of 1500 in two different pipes with relative roughness of 0.001 and 0.002. The friction factor

(a) Will be higher for the pipe with relative roughness of 0.001

(b) Will be higher for the pipe having relative roughness of 0.002

(c) Will be the same in both the pipes

(d) In the two pipes cannot be compared on the basis of data given

**Ques.** A liquid compressed in cylinder has a volume of 0.04 m° at 50 kg/cm^{2} and a volume of 0.039 m^{3} at 150 kg/cm^{2}. The bulk modulus of elasticity of liquid is

(a) 400 kg/cm^{2
}(b) 40 x 10^{6} kg/cm^{2}

(c) 40 x 10^{5} kg/cm^{2}

(d) 4000 kg/cm^{2}

**Ques.** A fluid jet is discharging from a 100 mm nozzle and the vena contracta formed has a diameter of 90 mm. If the coefficient of velocity is 0.95, then the coefficient of discharge for the nozzle is

(a) 0.7695

(b) 0.81

(c) 0.9025

(d) 0.855

**Ques.** A fully developed laminar viscous flow through a circular tube has the ratio of maximum velocity to average velocity as

(a) 3.0

(b) 2.0

(c) 2.5

(d) 1.5

**Ques.** If the surface tension of water-air interface is 0.073 N/m, the gauge pressure inside a rain drop of 1 mm diameter will be

(a) 0.146 N/m^{2}

(b) 73 N/m^{2}

(c) 146 N/m^{2}

(d) 292 N/m^{2}

**Ques.** Pitch diameter is equal to the product of

(a) Circular pitch and number of teeth

(b) Working depth and number of teeth

(c) Clearance and number of teeth

(d) Module and number of teeth

ISRO ME Paper Download: https://www.examsegg.com/downloads/isro-mechanical-engineering-paper-2011.pdf

### ISRO 2012 Paper Mechanical Engineering:

**Ques.** 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

**Ques.** Which bearing offers lowest friction

(a) hydrostatic Bearing

(b) Roller Bearing

(c) Aero- static Bearing

(d) Hydrodynamic Bearing

**Ques.** 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%

**Ques.** An elevator weighing l000 Kg 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 )

(a) 1204 N

(b) 9800N

(c) 2000N

(d) 11800N

**Ques.** 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. IfThe 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

**Ques.** A rotating disc of l m diameter has two eccentric masses of 0.5 kg each at radis of 50mm and 60mm at angular position of 0 and 150 , respectively. A balancing mass of 0.l Kg is to be used to balance the rotor. What is the radial position of balancing mass?

(a) 50 mm

(b) 120 mm

(c) 150 mm

(d) 280 mm

**Ques.** 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

**Ques.** 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

**Ques.** 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

**Ques.** The diameter of a soap bubble which has an inside pressure of 2.5 N/m 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

ISRO Mechanical Engineering PDF Paper Download: https://www.examsegg.com/downloads/isro-mechanical-engineering-paper-2012.pdf

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