MPSC Maharashtra Engineering [Mechanical] Services, Gr-B- 2014-Paper-2

MPSC Maharashtra Engineering [Mechanical] Services, Gr-B– 2014-Paper-2

  1. The portion of the internal energy of a system associated with the kinetic energies of the molecules is called

(1) Latent energy

(2) Sensible energy

(3) Potential energy

(4) Flow energy

  1. The first law of thermodynamics is essentially an expression of

(1) Conservation of mass principle

(2) Conservation of momentum principle

(3) Conservation of energy principle

(4) Conservation of air principle

  1. In a reversible cycle, the entropy of the system

(1) Increases

(2) Decreases

(3) Does not change

(4) First increases and then decreases

  1. The loci of saturated liquid line and saturated vapour line meet at

(1) Critical point

(2) Boiling point

(3) Ice point

(4) Triple point

  1. “The cyclic integral at 68/T is always less than zero” is called ‘Clausis Inequality’ and is valid for

(1) All cycles, reversible and irreversible

(2) Only reversible cycles

(3) Only irreversible cycles

(4) None of the above

  1. Availability Function is expressed as

(1) a = (U + PoV – ToS)

(2) a = (U + PodV + TodS)

(3) a=(dU+PodV-T o dS)

(4) a = (U + PoV + ToS)

  1. Multistage compression with inter-cooling is especially attractive when a gas is to be compressed at

(1) Very low pressure

(2) Normal pressure

(3) Very high pressure

(4) None of the above

  1. A beam of circular section is subjected to shear force. Then maximum shear stress across the section of beam is _______ greater than mean stress.

(1) 24%

(2) 29%

(3) 30.33%

(4) 33.33%

  1. When cantilever is loaded at its free end, then variation of bending stress across the section is

(1) Linear

(2) Parabolic

(3) Hyperbolic

(4) Elliptic

  1. Which of the following techniques does not require quenching to obtain final case hardness?

(1) Flame hardening

(2) Induction hardening

(3) Nitriding

(4) Carburizing

  1. As compared to the engineering stress – engineering strain curve, the true stress – strain curve for a given material

(1) Lies above and to the left

(2) Lies below and to the right

(3) Crosses the engineering stress – strain curve

(4) Is identical

  1. Regarding recrystallization, which of the following statements is not correct?

(1) Higher the amount of cold work, lower is the recrystallization temperature.

(2) Higher the recovery, higher is the recrystallization.

(3) Higher is the temperature of cold work, higher is the recrystallization temperature.

(4) Finer the initial grain size, higher is the recrystallization temperature.

  1. The microstructure of eutectoid steel is _________ at room temperature.

(1) Ferrite and pearlite

(2) Pearlite

(3) Ferrite and austenite

(4) Commentate

  1. The molten metal is forced through an orifice into a stream of high velocity air in ________ .

(1) Sintering

(2) Granulation

(3) Atomization

(4) Electrolysis

  1. Muntz metal is an alloy of ___________.

(1) Zinc and lead

(2) Copper and zinc

(3) Tin and zinc

(4) Lead and white metal

  1. Creep is specially taken care of while designing ________

(1) Turbine rotor and casing

(2) Drilling machines

(3) Shapers

(4) Refrigerators

  1. In white cast iron, carbon is present as ____________ .

(1) Graphite flakes

(2) Graphite nodules

(3) Combined cementite

(4) Carbon does not exist

  1. If the thermal conductivity is observed in decreasing order, which of the following lists is correct?

(1) Copper, Aluminium, Silver, Iron

(2) Silver, Copper, Aluminium, Iron

(3) Aluminium, Iron, Silver, Copper

(4) Iron, Silver, Copper, Aluminium

  1. Convective heat transfer coefficient depends

(1) Only on thermodynamic and transport property of carrier fluid

(2) Only on nature of fluid flow

(3) Only on geometry of surface and prevailing thermal conditions

(4) All of the above

  1. Time required to cool a heated copper ball depends on which of the following properties of copper ball?

(1) Thermal conductivity only

(2) Thermal conductivity and specific heat

(3) Specific heat only

(4) Thermal conductivity or specific heat

  1. Real surface in radiation heat transfer is

(1) Black body

(2) Gray body

(3) Having emissivity dependence on the wavelength of radiation

(4) None of the above

  1. If a heated plate is kept vertical in atmospheric air, its thermal boundary layer formation will be from

(1) Top end

(2) Bottom end,

(3) Midpoint of plate

(4) Simultaneously from both ends

  1. Plate heat exchanger does not have the following feature:

(1) Very high film conductance on both sides of plate

(2) Requires much lower floor area as compared to shell and tube heat exchanger

(3) Less costly than shell and tube type for costly construction material

(4) Difficult to clean

  1. Which statement is not true about Fick’s law of mass transfer?

(1) Mass diffusion is due to concentration gradient.

(2) The movement of a diffusion substance is in the direction of increasing concentration.

(3) Diffusion constant for ideal gases is assumed constant.

(4) Law is valid for all states of matter.

  1. Ratio of thermal diffusivity to mass diffusivity is designated by a non-dimensionless number, known as

(1) Schmidt number

(2) Sherwood number

(3) Lewis number

(4) Stanton number

  1. The ability of a material to absorb energy per unit volume without fracture is known as

(1) Toughness

(2) Resilience

(3) Stiffness

(4) Yield strength

  1. For ductile materials, design of shaft is based on which of the following failure theories?

(1) Maximum normal stress theory

(2) Maximum shear stress theory

(3) Distortion energy theory

(4) Von Mises theory

  1. A system of rotating masses is in dynamic balance, when there does not exist any _______ .

(1) Resultant centrifugal force

(2) Resultant couple

(3) Resultant centrifugal force as well as resultant couple

(4) Unbalanced mass

  1. In case of large guns, to achieve minimum return time, the damping coefficient is kept

(1) Greater than one

(2) Equal to one

(3) Less than one

(4) Equal to two

  1. When the shaft is bent alternately, and tensile and compressive stresses due to bending are developed, the vibrations in shaft are said to be

(1) Longitudinal

(2) Tensional

(3) Whirling

(4) Transverse

  1. Which of the following specialised industrial devices is used for interfacing to and controlling analog and digital devices?

(1) PID controller

(2) Adaptive control system

(3) Programmable logic controller

(4) PD controller

  1. “Microprocessors” which have memory and various input/out arrangements on the same chip are called ______.

(1) Buses

(2) Registers

(3) Micro controllers

(4) Attenuators

  1. Which of the following registers are used in microprocessor for temporary storage of operands or intermediate data in calculations?

(1) Instruction registers

(2) General purpose registers

(3) Stack pointers

(4) None of the above

  1. Because of high power-to-weight ratio, the hydraulic systems find a wide range of use in

(1) Machine tools

(2) Speed governing systems

(3) Position control systems

(4) All of the above

  1. For majority of the plant and process control actions in petroleum, petrochemical, textile and food industries, which of the following systems is preferably employed?

(1) Hydraulic

(2) Pneumatic

(3) Electrical

(4) None of the above

  1. Which of the following methods permits accurate computations of time-domain response in addition to yielding readily available frequency response information?

(1) Nyquist method

(2) Nichols chart

(3) Root locus method

(4) None of the above

  1. The transient response of a system is mainly due to

(1) Inertia forces

(2) Internal forces

(3) Stored energy

(4) Friction

  1. Programmable logic controllers (PLC’s) consist of CPU, memory and _____ circuitry as main components.

(1) Optical sensors

(2) input/output

(3) position control system

(4) None of the above

  1. The variation in the speed of the wheels along a curvature, for a four wheeled passenger car, is accomplished by which of the following?

(1) Sliding mesh gear box

(2) Synchromesh gear box

(3) Differential gear box

(4) Preselective gear box

  1. Which of the following governors is mostly used to drive a gramophone?

(1) Pickering governor

(2) Watt governor

(3) Porter governor

(4) None of the above

  1. A Hartnell governor is a______

(1) Pendulum type governor

(2) Spring loaded governor

(3) Dead weight governor

(4) Inertia governor

  1. The engine of an aeroplane rotates in a clockwise direction, when seen from the tail end and the aeroplane takes a turn to the left. The effect of the gyroscopic couple on the aeroplane will be

(1) To dip the nose and tail

(2) To raise the nose and tail

(3) To dip the nose and raise the tail

(4) To raise the nose and dip the tail

  1. If the speed of the engine controlled by the governor fluctuates continuously above and below the mean speed, the governor is said to be ___________ .

(1) Stable

(2) Unstable

(3) Isochronous

(4) Hunting

  1. Hammer blow is the maximum amplitude of the unbalanced force at an angle _________ with the line of stroke.

(1) 00

(2) 450

(3) 900

(4) 1800

  1. The swaying couple is maximum or minimum when the angle of inclination of the crank with the line of stroke is equal to _____ .

(1) 250 and 1150

(2) 600 and 1500

(3) 1200 and 3100

(4) 450 and 2250

  1. Direct and Reverse crank method makes the analysis of forces simple in case of ________ .

(1) V-engine

(3) Radial engine

(2) In-line engine

(4) None of the above

  1. The tractive force is maximum or minimum when the angle of inclination of the crank with the line of stroke is equal to ______.

(1) 90°and 1350

(2) 1350 and 3150

(3) 450 and 1350

(4) 1350 and 1800

  1. The most common method of obtaining rich mixture during cold starting is

(1) Acceleration pump system

(2) Main metering system

(3) Idling system

(4) Application of choke

  1. Which one of the following lubricating systems is used for two stroke IC engines?

(1) Wet sump lubricating system

(2) Dry sump lubricating system

(3) Mist lubricating system

(4) Splash lubricating system

  1. The second stage of combustion in C.I. engines after the delay period, is the period of

(1) Physical delay

(2) Uncontrolled combustion

(3) Controlled combustion

(4) After burning

  1. The _______ cooling system cannot be used in high output engines due to its inability to meet the requirement of large flow rates of water.

(1) Evaporative

(2) thermo-syphon

(3) Cooling with thermostatic regulator

(4) pump cooling

  1. The ignition of the homogeneous mixture in the cylinder, before the timed ignition spark occurs, is known as

(1) Delay period

(2) Pre-ignition

(3) Post ignition

(4) None of the above

  1. The ignition lag time in SI Engine is normally about

(1) 0.01 seconds

(2) 0.0015 seconds

(3) 0.1 seconds

(4) 1.1 seconds

  1. Dissociation refers to disintegration of burnt gases at high temperatures and it is a/an

(1) Reversible process

(2) Irreversible process

(3) Quasi-static process

(4) None of the above

  1. Which one of the following is true for fuel air cycles?

(a) There is no chemical change in either fuel or air prior to combustion.

(b) Subsequent to combustion, the charge is always in chemical equilibrium.

(1) Only (a)

(2) Only (b)

(3) Both (a) and (b)

(4) None of the above

  1. Which one of the following describes turbochargers of the engines? (a) Centrifugal compressors driven by the exhaust gas turbines. (b) Turbochargers will not draw upon the engine power.

(1) Only (a)

(2) Only (b)

(3) Both (a) and (b)

(4) None of the above

  1. Which of the following casting processes is widely used for making ornamental objects?

(1) Centrifugal casting

(2) Slush casting

(3) Investment casting

(4) Gravity die casting

  1. If the hot working is completed much above the recrystallization temperature, then

(1) The grain size starts decreasing and final grain size will be smaller than at starting.

(2) The resulting grain size will be fine.

(3) The grain size starts increasing and finally may end up as coarse grain size.

(4) The grain size is reduced and a large number of nucleation sites are developed for new crystals to form.

  1. In Resistance welding, the factor R (Resistance of joint) is composed of

(i) Resistance of electrodes

(ii) Contact resistance between the electrode and the work-piece

(iii) Contact resistance between the two work-piece plates

(iv) Resistance of work-piece plates

(1) Only (i) and (ii)

(2) Only (ii) and (iii)

(3) Only (i) and (iv)

(4) All (i), (ii), (iii) and (iv)

  1. The powder metallurgy technique is applicable for

(1) Job type production

(2) Batch type production

(3) Mass type production

(4) None of the above

  1. Polymers usually consist of carbon plus one or more other elements, such as

(i) Hydrogen

(ii) Nitrogen

(iii) Oxygen

(iv) Chlorine

(1) Only (i) and (iii)

(2) Only (ii) and (iii)

(3) Only (i) and (iv)

(4) All (i), (ii), (iii) and (iv)

  1. In a CNC program block

NO02 GO2 G91 X40 240

GO2 and G91 refer to

(1) Circular interpolation in counter-clockwise direction and incremental dimension

(2) Circular interpolation in counter-clockwise direction and absolute dimension

(3) Circular interpolation in clockwise direction and incremental dimension

(4) Circular interpolation in clockwise direction and absolute dimension

  1. In orthogonal cutting, shear angle is the angle between

(1) Shear plane and the direction of tool travel

(2) Shear plane and the rake plane

(3) Shear plane and the vertical direction

(4) Shear plane and the direction of elongation of crystals in the chip

  1. Chipping of the tool may occur

(i) due to tool material being too brittle

(ii) As a result of crack in the tool

(iii) Due to excessive static loading of the tool

(iv) Due to weak design of the tool

(1) Only (i) and (ii)

(2) All (i), (ii), (iii) and (iv)

(3) Only (ii) and (iii)

(4) Only (i) and (iii)

  1. Subsonic diffuser section is __________ .

(1) divergent

(2) divergent-convergent

(3) convergent

(4) convergent-divergent

  1. At sonic speed, Mach angle is _______ .

(1) 00

(2) 900

(3) 300

(4) 600

  1. The assumption not made in the derivation of Bernoulli equation is __________ .

(1) in viscid flow

(2) steady flow

(3) two-dimensional flow

(4) uniform flow

  1. The number of buckets for Pelton wheel with 30 cm runner diameter and 5 cm jet diameter is _______.

(1) 20

(2) 16

(3) 18

(4) 24

  1. Minimum speed for starting delivery in a centrifugal pump depends on _________ .

(1) overall efficiency

(2) mechanical efficiency

(3) volumetric efficiency

(4) manometric efficiency

  1. The volumetric efficiency of a reciprocating air compressor depends on _________ .

(1) pressure ratio only

(2) clearance ratio only

(3) both pressure ratio and clearance ratio

(4) clearance volume

  1. Slip in the case of a centrifugal pump ______.

(1) reduces the flow rate

(2) reduces the energy transfer

(3) reduces the speed

(4) increases cavitation

  1. In a measurement system, which of the following static characteristics are desirable?

(1) Accuracy

(2) Sensitivity

(3) Reproducibility

(4) All of the above

  1. Linear Variable Differential Transformer (LVDT) can be used to measure displacement ranging from

(1) 1.25 mm to 250 mm

(2) 260 mm to 270 mm

(3) 280 mm to 290 mm

(4) All of the above

  1. Dummy strain gauges are used for

(1) compensation of temperature changes

(2) calibration of strain gauge

(3) increasing the sensitivity of bridge circuit in which they are included

(4) None of the above