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1. What is the range of percentage of carbon in cast iron? (1)

2.5%

2. Distinguish between creep and fatigue. (2)

Creep is low and progressive deformation of a material with time under a constant stress at hightemperature applications. Fatigue is the reduced tendency of material to offer resistance to

applied stress under repeated or fluctuating loading condition.

3. What is the standard firing order of 4 cylinder petrol engine? (1)

1-3-4-2

4. What is after burning in turbojet engines. (1)

An afterburner (or reheat) is an additional component added to some jet engines, primarily

those on military supersonic aircraft. Its purpose is to provide a temporary increase in thrust,both for supersonic flight and for takeoff (as the highwing loadingtypical of supersonic aircraft

designs means that take-off speed is very high). Onmilitary aircraftthe extra thrust is also usefulforcombatsituations. This is achieved by injecting additionalfuelinto the jet pipe downstream

(i.e. after) of the turbine. The advantage of afterburning is significantly increased thrust; the

disadvantage is its very high fuel consumption and inefficiency, though this is often regarded asacceptable for the short periods during which it is usually used.

5. What is endurance limit and what is its value for steel in terms of its yield strength?(1)

Endurance limit is the maximum level of fluctuating stress which can be tolerated indefinitely.In most steels this stress is approximately 50% of the ultimate tensile strength and it is defined as

the stress which can be endured for ten million reversals of stress

6. Convergent-Divergent Nozzle are used for ___________________________ (1)

It is widely used in some types ofsteam turbineand is an essential part of the modernrocket

engineand supersonicjet engines

7. Why is runner required for casting? (1)

The sprue then connects to a series of channels, called runners, which carries the molten metal

into the cavity. At the end of each runner, the molten metal enters the cavity through a gate

which controls the flow rate and minimizes turbulence.

8. How can the hollow shapes be formed without cores? (1)

http://en.wikipedia.org/wiki/Jet_enginehttp://en.wikipedia.org/wiki/Jet_enginehttp://en.wikipedia.org/wiki/Supersonichttp://en.wikipedia.org/wiki/Supersonichttp://en.wikipedia.org/wiki/Thrusthttp://en.wikipedia.org/wiki/Thrusthttp://en.wikipedia.org/wiki/Wing_loadinghttp://en.wikipedia.org/wiki/Wing_loadinghttp://en.wikipedia.org/wiki/Wing_loadinghttp://en.wikipedia.org/wiki/Military_aircrafthttp://en.wikipedia.org/wiki/Military_aircrafthttp://en.wikipedia.org/wiki/Military_aircrafthttp://en.wikipedia.org/wiki/Aerial_combathttp://en.wikipedia.org/wiki/Aerial_combathttp://en.wikipedia.org/wiki/Aerial_combathttp://en.wikipedia.org/wiki/Jet_fuelhttp://en.wikipedia.org/wiki/Jet_fuelhttp://en.wikipedia.org/wiki/Jet_fuelhttp://en.wikipedia.org/wiki/Turbinehttp://en.wikipedia.org/wiki/Turbinehttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Rocket_enginehttp://en.wikipedia.org/wiki/Rocket_enginehttp://en.wikipedia.org/wiki/Rocket_enginehttp://en.wikipedia.org/wiki/Rocket_enginehttp://en.wikipedia.org/wiki/Jet_engineshttp://en.wikipedia.org/wiki/Jet_engineshttp://en.wikipedia.org/wiki/Jet_engineshttp://en.wikipedia.org/wiki/Jet_engineshttp://en.wikipedia.org/wiki/Rocket_enginehttp://en.wikipedia.org/wiki/Rocket_enginehttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Turbinehttp://en.wikipedia.org/wiki/Jet_fuelhttp://en.wikipedia.org/wiki/Aerial_combathttp://en.wikipedia.org/wiki/Military_aircrafthttp://en.wikipedia.org/wiki/Wing_loadinghttp://en.wikipedia.org/wiki/Thrusthttp://en.wikipedia.org/wiki/Supersonichttp://en.wikipedia.org/wiki/Jet_engine

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9. A trolley wire weighs 1.2 kg per metre length. The ends of the wire are attached to

two poles 20m apart. If the horizontal tension is 1500 kg, find the dip in the middle of the

span. (2)

4 cm

10. Define: Point of Contraflexure (2)

In a bendingbeam, a point is known as a point ofcontraflexure if it is a location at which no

bending occurs. In a bendingmomentdiagram, it is the point at which the bending moment curveintersects with the zero line. Knowing the place of the contraflexure is especially useful when

designingreinforced concretebeams and also for designing bridges.

11. What is a lumped system? (1)

Alumped systemis one in which the dependent variables of interest are a function of time alone.

In general, this will mean solving a set of ordinarydifferential equations(ODEs)

12. Why is involute curve universally used as gear tooth profile? (1)

Involute curve satisfies the law of gearing

13. What do you understand by the term proof stress? (1)

The stress that will cause a specified small, permanent extension of a tensile test piece.Commonly the stress to produce 0.2% extension is quoted in N/mm2 for steel. This value

approximates to the yield stress in materials not exhibiting a definite yield point.

14. What are Reynolds and Mach number? Write down their expressions. (2)

Influid mechanics, the Reynolds number Re is adimensionless numberthat gives a measure of

theratioofinertialforces toviscousforces and consequently quantifies therelative importance of these two types of forces for given flow conditions.

[

Mach number (Ma orM) (generally pronounced/mk/, sometimes /mx/ or /mk/) is the

speed of an object moving through air, or anyfluidsubstance, divided by thespeed of soundas itis in that substance.

15. What are the functions of the flux used in Submerged Arc Welding? (1)

http://en.wikipedia.org/wiki/Beam_(structure)http://en.wikipedia.org/wiki/Beam_(structure)http://en.wikipedia.org/wiki/Beam_(structure)http://en.wikipedia.org/wiki/Moment_(physics)http://en.wikipedia.org/wiki/Moment_(physics)http://en.wikipedia.org/wiki/Moment_(physics)http://en.wikipedia.org/wiki/Reinforced_concretehttp://en.wikipedia.org/wiki/Reinforced_concretehttp://en.wikipedia.org/wiki/Reinforced_concretehttp://search.freefind.com/find.html?id=3891388&pageid=r&mode=ALL&query=Lumped+Systemhttp://search.freefind.com/find.html?id=3891388&pageid=r&mode=ALL&query=Lumped+Systemhttp://search.freefind.com/find.html?id=3891388&pageid=r&mode=ALL&query=Lumped+Systemhttp://mathworld.wolfram.com/DifferentialEquation.htmlhttp://mathworld.wolfram.com/DifferentialEquation.htmlhttp://mathworld.wolfram.com/DifferentialEquation.htmlhttp://scienceworld.wolfram.com/math/OrdinaryDifferentialEquation.htmlhttp://scienceworld.wolfram.com/math/OrdinaryDifferentialEquation.htmlhttp://scienceworld.wolfram.com/math/OrdinaryDifferentialEquation.htmlhttp://en.wikipedia.org/wiki/Fluid_mechanicshttp://en.wikipedia.org/wiki/Fluid_mechanicshttp://en.wikipedia.org/wiki/Fluid_mechanicshttp://en.wikipedia.org/wiki/Dimensionless_numberhttp://en.wikipedia.org/wiki/Dimensionless_numberhttp://en.wikipedia.org/wiki/Dimensionless_numberhttp://en.wikipedia.org/wiki/Ratiohttp://en.wikipedia.org/wiki/Ratiohttp://en.wikipedia.org/wiki/Ratiohttp://en.wikipedia.org/wiki/Inertiahttp://en.wikipedia.org/wiki/Inertiahttp://en.wikipedia.org/wiki/Inertiahttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Reynolds_number#cite_note-3http://en.wikipedia.org/wiki/Reynolds_number#cite_note-3http://en.wikipedia.org/wiki/Wikipedia:IPA_for_Englishhttp://en.wikipedia.org/wiki/Wikipedia:IPA_for_Englishhttp://en.wikipedia.org/wiki/Wikipedia:IPA_for_Englishhttp://en.wikipedia.org/wiki/Wikipedia:IPA_for_Englishhttp://en.wikipedia.org/wiki/Wikipedia:IPA_for_Englishhttp://en.wikipedia.org/wiki/Wikipedia:IPA_for_Englishhttp://en.wikipedia.org/wiki/Wikipedia:IPA_for_Englishhttp://en.wikipedia.org/wiki/Wikipedia:IPA_for_Englishhttp://en.wikipedia.org/wiki/Fluidhttp://en.wikipedia.org/wiki/Fluidhttp://en.wikipedia.org/wiki/Fluidhttp://en.wikipedia.org/wiki/Speed_of_soundhttp://en.wikipedia.org/wiki/Speed_of_soundhttp://en.wikipedia.org/wiki/Speed_of_soundhttp://en.wikipedia.org/wiki/Speed_of_soundhttp://en.wikipedia.org/wiki/Fluidhttp://en.wikipedia.org/wiki/Wikipedia:IPA_for_Englishhttp://en.wikipedia.org/wiki/Reynolds_number#cite_note-3http://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Inertiahttp://en.wikipedia.org/wiki/Ratiohttp://en.wikipedia.org/wiki/Dimensionless_numberhttp://en.wikipedia.org/wiki/Fluid_mechanicshttp://scienceworld.wolfram.com/math/OrdinaryDifferentialEquation.htmlhttp://mathworld.wolfram.com/DifferentialEquation.htmlhttp://search.freefind.com/find.html?id=3891388&pageid=r&mode=ALL&query=Lumped+Systemhttp://en.wikipedia.org/wiki/Reinforced_concretehttp://en.wikipedia.org/wiki/Moment_(physics)http://en.wikipedia.org/wiki/Beam_(structure)

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16. Explain the difference between conventional milling and climb milling. (2)

When milling, one should be aware of the difference between conventional,and climb milling. In

conventional milling, the workpiece is fed into the rotation of the cutter. This type of cut requireslower forces and is preferred for roughing cuts. In climb milling, the work moves with the

rotation of the cutter. This produces a better finish. It is not recommended if the workpiece

cannot be held securely or cannot support high forces.

Conventional Milling Climb Milling

17. What do you mean by drill sleeve and drill socket? (1)

A tapered, hollow steel shaft designed to fit the tapered shank of a cutting tool to adapt itto the drill press spindle An adapter to fit a tapered shank drill to a taper hole that is larger than that in the drill

press spindle.

18. Differentiate between turbocharger and supercharger. (2)

A supercharger is mechanically driven by the engine; a turbocharger is driven by streaming

exhaust gas.

19. What are the problems encountered while welding cast iron? (1)

pre-heat the weld slowly.Use a nickel rod and weldCover with something to make sure the weld cools slowly.

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20. What is slenderness ratio in power screws? (1)

It is the ratio of unsupported length to the minimum radius of gyration

21. Why does slip occur in belt drive? (1)

Slip occurs due to unequal elongation of belt due to tight and slack side tensions

22. Define: Boundary layer (2)

It is the fluid layer in the neighbourhood of a solid boundary where the effects of fluid friction

are predominant

23. What are the three functions served by a surge tank in a hydro plant? (1)

Flow regulationWater-hammer relief or pressure regulation

Improvement in speed regulation

24. When does a kinetic chain become a kinematic mechanism? (1)

When any one link is fixed

25. What is Kleins construction? (1)

It is a graphical procedure of drawing acceleration diagram for a slider crank mechanism

26. Which is the most suitable bearing for carrying heavy loads at low speeds? (1)

Hydrostatic bearing

27. What is One ton of refrigeration in terms of kW? (1)

1 tonne of refrigeration = 13898 kJ/h = 3.861kW.28. Define COP of heat pump operating on reversed Carnot cycle (2)

Ratio of heat rejected and workdone

29. Name the Turbine for which Flow through rotor blades is substantially at constant

static pressure. (1)Impulse

30. What is critical insulation thickness? (1)

Addition of insulation increases the heat loss upto a certain thickness only. Its value is the ratio

of thermal conductivity and the heat transfer coefficient.

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31. Why large boilers are water tube type? (1)

Water tube boilers raise steam fast because of large heat transfer area and positive water

circulation. Thus they respond faster to fluctuations in demand. Further single tube failure doesnot lead to catastrophy.

32. What are two essential conditions of perfect gas? (1)

It satisfies equation of state and its specific heats are constant

33. What is the latent heat of evaporation at critical point? (1)

The heat of vaporization is temperature-dependent, though a constant heat of vaporization can be

assumed for small temperature ranges and belowTr

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40. Distinguish between brazing and soldering? (2)

Brazing

High melting point alloys are used

The filler metal is known as spelter

Strength of joint is highJoining of dissimilar metals pipe and fittings

Process is done below the melting point of filler metal

Soldering

Low melting point alloys are used

Filler metal is known as solderStrength of joint is relatively low

Mainly used for electrical connections

Process is done at melting point of filler metal