HAL mechanical papers and syllabus

I am going to appear for the HAL recruitments exam so will you please provide me the HAL mechanical question papers of previous years and also provide me the syllabus of it?

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Hindustan Aeronautics Limited is situated in Bangalore, India. It is one of Asia's largest aerospace companies. It is running under the management of the Indian Ministry of Defence. It is a state-owned company is mainly involved in aerospace industry.

HAL question papers
As you are asking about the HAL mechanical question papers so for your help here I am giving it to you:

HAL Sample Test Paper

1. When length of a wire increases its resistance
a. doubles
b. half
c. remains same
Ans: ( a )

2. When a 50 Hz ,6-pole Induction Motor runs at 975rpm,the rotor emf frequency is
a. 12.5Hz
b. 1.25Hz
c. 4Hz
Ans: ( b )

3. When a 6 pole 50Hz Induction Motor runs at 1450 rpm , it’s working mode is
a. motoring
b. braking
c. generating

Ans: ( a )

4. Slips for Different modes of operation of Induction Motor are
answer: motoring -0<S<1,generating- S<0,braking - S>1

5. Damping ratio ( ? ) is 0.75, natural frequency is 12 rad/s are given & asked to find peak time

6. In electrodynamo-meter type wattmeter
a. pressure coil is made fixed
b. current coil is made fixed
c. both the coils are made fixed
Ans: ( a )

7. In flux meter control torque is produced by
a. weights attached to it.
b. Springs
c. No control torque is there
Ans: ( c )

8. One question regarding hot wire instrument

9. In MI meters deflecting torque is proportional to
a. square of the current
b. square of the voltage
Ans: ( a )

10.In 3-F system total power is given by
a. v3VLILcos F
b. 3VLILcos F
c. VLILcos F
Ans: ( a )

11.From supply one 3-F step-down transformer is drawing 10 A, the secondary current will be minimum when the transformer is
a. star-delta
b. delta-star
c. delta-delta
d. star-star
Ans: ( b )

12.Transformer rating is expressed in
a. KVA
b. KVAR
c. KW
Ans: ( a )


13.Manganin is a
a. Insulator
b. Semi-conductor
c. Alloy

14.Dual scope oscilloscope has
a. two separate horizontal and two separate vertical plates
b. one horizontal and two separate vertical plates
c. two separate horizontal and one vertical plates
d. one horizontal and one vertical plates

15.Standard Cell voltage is measured by
a. MI meter
b. MC meter
c. Potentiometer

16.The input resistance of the CRO is of the order of
a. tens of ohm
b. mega ohm
c. kilo ohm
d. fraction of an ohm
Ans: ( b )

17.Errors are introduced in Wheatstone bridge due to
a. lead resistance
b. contact resistance
c. some thing is given
d. all of the above

18.HRC fuse and circuit-breaker combination is used CB operates for
a. low over-load currents
b. high over-load currents
c. combination is never used

19.G(s) = K / s(s+5)(s+1) is given to find the value of K for stable operation

20.By increasing gain of the system root locus will
a. moves away from poles
b. moves away from zeros
c. crosses imaginary axis
Ans: ( a )

21.When the load current is high while measuring power using wattmeter
a. current coil is connected near load
b. pressure coil is connected near load

22.C = 0.01µF and L = 1 mH and current is 10 A and asked to find the voltage drop

23.Transmission line is terminated by R and no reflection is there , then the value of R is
_________
Ans: 400 ohm

24.One question regarding shunt ohm-meter and seriea ohm-meter

25.Inverted V curves are drawn between ________

Ans: field current Vs power factor


1) The purpose of feedback transformer & diode in complementary commutated inverters is to-

2) In order to obtain static voltage equalization in series connected SCR’s connection r made of- (this question repeatedquestion)

3) In phase controlled rectification PF=

4) Why sector winding is used in synchronous motor?

5) A calculation of making current where MVA & KV was given.

6) The oop voltage e1 & e2 of 2 full-bridge inverters added using o/p transformer. In order to eliminate 5th harmonic from o/p voltage, the phase angle between e1&e2 will be-

7) A single phase fully controlled line commutated ac-dc converter operates as an inverter when-

8) An SCR has half cycle surge current rating of 3000A for 50Hz. One cycle surge current will be. (double of that)

9) When compared to an symmetrical thyristor, the turn off time & reverse blocking voltage of an asymmetrical thyristor will be-

10) A step-up chopper is feed from an 220v dc source to deliver a load voltage of 66o v. If the non conducting time is 100micro-sec then reqd pulse width will be. (get duty cycle only)

11) There were some 5-6 numerical problems which I could not remember totally but they consist of firing angle & power transfer of inverter, SCR. Go llok for that.

12) Relay current setting & Ct ratio was given you have to find out Relay Pick up Current.

13) One question from Dc shunt motor- like a resistance is added of 4.5 ohm in series with arm where rest of arm is 0.5 ohm. Machine is supplied 220v. find out the null current.

14) In aptitude part see through series completion there was a 5-6 no of that.

15) No aptitude questing like avg, %, proff-loss, prob, etc.

17) Why rotor of SCIM is skewed?

19) Good transformer oil contains how much amount of water in ppm?

20) Lightning over voltage create how much volt?

21) K/s(s+1)(s+5) then find out the value of K so that system become stable.

22) There was a question from definition of Nyquist criteria.

23) Standing done up to the frequency range of? (audio)

24) If a square waveform if given to the supply side of a 2wdg transformer its o/p waveform will be-

25) SC test done on transformer because....

26) If a transformer is operating in .8 PF lag & at efficiency of .9, if now P is .8 lead the efficiency will become.

27) Interpoles are connected for?

28) Dielectric strength of air?

29) A alternator is connected to a grid. Now its prime mover is go slow by ½. Change in its exiting current to held in synchronism.

30) Is the strength of capacitor in LPF is increased the op voltage will-

31) The voltage of a generator and an infinite bus are given 0.92, 10 deg & 1.0, 0 deg resp. the generator acts as a –

32) A wave will not experience any reflection when impedance of line is equal to- surge imp

33) Power transmitted is related to system voltage as-

34) Delay creator ckt name (multivibrator name actually)

35) In tachogenerator adjustment is done by-

36) Surge wave is attended by- (C,L,R)

37) there was 10 question related to measurement-

38) Read all electrostatic instrument related question from any competitive exam book.

39) Lowest reading in moving iron meter is-

40) In galvanometer damping is provided by-

41) In electrodynamic meter a battery & a resistance is provide for-

42) Megger is used for-

43) A question like an ac is applied against a moving coil meter it will reads-

44) Rectifier type instrument measureswhat value - (Rms)

45) Advantage of electrostatic instrument is-

46) Creeping occurs because-

47) Why 2 holes are drilled oppositely in disc of energy meter.

48) Energy meter is a _____ type equipment (recording)

49) There was a question related to selection of a voltmeter based on accuracy-

50) Advantage of hay bridge over anderson bridge-

51) Inductance is measured by – (all the 3 bridge name) .

52) Potentiometer is which type of instrument-

53) Which type of motor is used in refrigerator?

54) Reflection coefficient based problem 1

55) Corona’s advantage-

Syllabus:
1. Thermodynamics.
Thermodynamics, Cycles and IC Engines, Basic concepts, Open and Closed systems. Heat and work. Zeroth, First and Second Law, Application to non-Flow and Flow processes. Entropy, Availability, Irreversibility and Tds relations. Claperyron and real gas equations, Properties of ideal gases and vapours. Standard vapour, Gas power and Refrigeration cycles. Two stage compressor. C-I and S.I. Engines. Pre-ignition, Detonation and Diesel-knock, Fuel injection and Carburation, Supercharging. Turbo-prop and Rocket engines, Engine Cooling, Emission & Control, Flue gas analysis, Measurement of Calorific values. Conventional and Nuclear fuels, Elements of Nuclear power production.

2. Heat Transfer and Refrigeration and Airconditioning.
Heat Transfer and Refrigeration and Airconditioning. Modes of heat transfer. One dimensional steady and unsteady conduction. Composite slab and Equivalent Resistance. Heat dissipation from extended surfaces, Heat exchangers, Overall heat transfer coefficient, Empirical correlations for heat transfer in laminar and turbulent flows and for free and forced Convection, Thermal boundary layer over a flat plate. Fundamentals of diffusive and connective mass transfer, Black body and basic concepts in Radiation, Enclosure theory, Shape factor, Net work analysis. Heat pump and Refrigeration cycles and systems, Refrigerants. Condensers, Evaporates and Expansion devices, Psychrometry, Charts and application to air conditioning, Sensible heating and cooling, Effective temperature, comfort indices, Load calculations, Solar refrigeration, controls, Duct design.

3. Fluid Mechanics.
Properties and classification of fluids, Manometry, forces on immersed surfaces, Center of pressure, Buoyancy, Elements of stability of floating bodies. Kinematics and Dynamics. Irrotational and incompressible. Inviscid flow. Velocity potential, Pressure field and Forces on immersed bodies. Bernoulli's equation, Fully developed flow through pipes, Pressure drop calculations, Measurement of flow rate and Pressure drop. Elements of boundary layer theory, Integral approach, Laminar and tubulent flows, Separations. Flow over weirs and notches. Open channel flow, Hydraulic jump. Dimensionless numbers, Dimensional analysis, Similitude and modelling. One-dimensional isentropic flow, Normal shock wave, Flow through convergent - divergent ducts, Oblique shock-wave, Rayleigh and Fanno lines.

4. Fluid Machinery and Steam Generators.
Performance, Operation and control of hydraulic Pump and impulse and reaction Turbines, Specific speed, Classification. Energy transfer, Coupling, Power transmission, Steam generators Fire-tube and water-tube boilers. Flow of steam through Nozzles and Diffusers, Wetness and condensation. Various types of steam and gas Turbines, Velocity diagrams. Partial admission. Reciprocating, Centrifugal and axial flow Compressors, Multistage compression, role of Mach Number, Reheat, Regeneration, Efficiency, Governance.

5. THEORY OF MACHINES:
Kinematic and dynamic analysis of planer mechanisms. Cams. Gears and gear trains. Flywheels. Governors. Balancing of rigid rotors and field balancing. Balancing of single and multicylinder engines, Linear vibration analysis of mechanical systems. Critical speeds and whirling of shafts Automatic controls.

6. MACHINE DESIGN :
Design of Joints : cotters, keys, splines, welded joints, threaded fasteners, joints formed by interference fits. Design of friction drives : couplings and clutches, belt and chain drives, power screws. Design of Power transmission systems : gears and gear drives shaft and axle, wire ropes. Design of bearings : hydrodynamics bearings and rolling element bearings.

7. STRENGTH OF MATERIALS
Stress and strain in two dimensions, Principal stresses and strains, Mohr's construction, linear elastic materials, isotropy and anisotropy, stress-strain relations, uniaxial loading, thermal stresses. Beams : Bending moment and shear force diagram, bending stresses and deflection of beams. Shear stress distribution. Torsion of shafts, helical springs. Combined stresses, thick-and thin-walled pressure vessels. Struts and columns. Strain energy concepts and theories of failure.

8. ENGINEERING MATERIALS :
Basic concepts on structure of solids. Crystalline maferials. Detects in crystalline materials. Alloys and binary phase diagrams. Structure and properties of common engineering materials. Heat treatment of steels. Plastics, Ceramics and composite materials. Common applications of various materials.

9. PRODUCTION ENGINEERING :
Metal Forming : Basic Principles of forging, drawing and extrusion; High energy rate forming; Powder metallurgy.
Metal Casting : Die casting, investment casting, Shall Moulding, Centrifugal Casting, Gating & Riser design; melting furnaces. Fabrication Processes : Principles of Gas, Arc, Shielded arc Welding; Advanced Welding Processes, Weldability: Metallurgy of Welding.
Metal Cutting : Turning, Methods of Screw Production, Drilling, Boring, Milling, Gear Manufacturing, Production of flat surfaces, Grinding & Finishing Processes. Computer Controlled Manufacturing Systems-CNC, DNC, FMS, Automation and Robotics.
Cutting Tools Materials, Tool Geometry, Mechanism of Tool Wear, Tool Life & Machinability; Measurement of cutting forces. Economicsof Machining. Unconventional Machining Processes. Jigs and Fixtures. Fits and tolerances, Measurement of surface texture, Comparators Alignment tests and reconditioning of Machine Tools.

10. INDUSTRIAL ENGINEERING :
Production Planning and Control : Forecasting - Moving average, exponential smoothing, Operations, scheduling; assembly line balancing, Product development, Break-even analysis, Capacity planning, PERT and CPM.
Control Operations : Inventory control ABC analysis, EOQ model, Materials requirement planning. Job design, Job standards, Work measurement, Quality Management - Quality analysis and control. Operations Research : Linear Programming - Graphical and Simplex methods, Transportation and assignment models. Single server queueing model. Value Engineering : Value analysis for cost/value.

11. ELEMENTS OF COMPUTATION :
Computer Organisation, Flow charting, Features of Common computer Languages - FORTRAN, d Base III, Lotus 1-2-3, C and elementary Programming.