339132575-mechanical-gate-test-series-madeeasy-2017

357. A pipe carries a stream of brine with a mass flow rate of 5 kg/s. Due to poor thermal
insulation, the brine temperature increases from 250 K at the pipe inlet to 253 K at the exit.
What is the irreversibility rate? Neglecting pressure losses. (Take To = 293K and cp = 2.85
kJ/kgK)

358. The value of integral is equal to

359. A 5 mm diameter and 10 m long electric wire is tightly wrapped with a 1 mm thick
plastic cover where thermal conductivity is 0.1 W/mK. Electrical measurements indicate that
a current of 10A passes through the wire and there is a voltage drop 8V. The insulated wire is
exposed to a medium at temperature 30°C and the temperature at the interface of the wire
and plastic cover in steady operation is 105°C. Keeping the current and voltage drop through
the wire constant, the change in the plastic cover thickness (in mm) that gives the minimum
interface temperature is ___________ .

360. A thermocouple, the junction of which can be approximated as 6mm diameter sphere
is used to measure the temperature of a gas stream. The properties of the junction are ρ =
8500 kg/m3, c = 320 J/kg-K and k = 35 W/m-K. The heat transfer coefficient between the
junction and gas is 210 W/m2-K. The time required for the thermocouple to read 90% of the
initial temperature difference is ___________ s.

361. A Brayton cycle operates at a pressure ratio which is 75% of the pressure ratio where
the degree of regeneration becomes zero. The efficiency of this cycle is 45%. The ratio of
maximum to minimum absolute temperature is _________.

362. A Rankine cycle operates between pressures of 80 bar and 0.1 bar. The maximum
cycle temperature is 750°C. The steam turbine and condensate pump efficiencies are 0.9 and
0.8 respectively. If the heat added in the boiler is 3500 kJ/kg and the thermal efficiency is
30%, the dryness fraction of steam at the turbine exit is ___________.

Relevant steam table is given below.

363. Cylindrical bars of 100 mm diameter and 576 mm length and turned in a single pass
operation. The spindle speed used is 144 rpm and the total feed is 0.2 mm/rev. Taylor’s tool
life relationship is VT0.75 = 75, where V is the cutting speed (m/min) and T is the tool life
(min). The time required to produce one piece is __________ minutes. (Given that the
handling time is 4 min, and it takes 3 min to change the tool each time).

364. For a period of 4 hours in a day (8 AM to 12 AM) trains arrive at the yard every 20
minutes but the service time is 42 minutes. If the line capacity of the yard is limited to 5
trains, the probability (in percentage) that the yard is empty is _________.

Four new machines M1, M2, M3 and M4 are to be installed in a machine shop. There are five
vacant places A, B, C, D and E available. Because of limited space, machine M2 cannot be
placed at C and M3 cannot be placed at A. Cij, the assignment cost of machine i to place j in
rupees is shown below:

The total assignment cost in rupees is _________.

365. The angle, at which a 500 mm diameter regulating wheel, running at 67 m/min, be set
to have a workpiece feed rate of 0.3 m/min, is _____________ degree.

Consider the following statements related to forging:
1. Flash is excess material added to stock which flows around parting line.

2. Flash helps in filling of thin ribs and bosses in upper die.
3. Amount of flash depends upon forging force.

1 and 2
366. If the T-beam cross-section shown in the given figure, has bending stress of 30 MPa in

top fibre, then the stress in the bottom fibre will be (G is centroid)

367. A solid shaft is welded to a flat plate by a t mm fillet weld. The maximum torque that
the joint can sustain is T Nm. If the permissible stress in the weld material is not to exceed τ
N/m,2, then which of the following is the correct expression for diameter d of the shaft ?

368. In a two dimensional stress analysis, the state of stress at a point is as shown below:
What is the value of shear stress, τ ?

The parameters which determine the friction factor for turbulent flow in a rough pipe are:
 Reynolds number and relative roughness
369. The mean diameter of the blades of an impulse turbine with a single row wheel is 100
cm and the speed is 3000 rpm. The power developed by the turbine is 520 kW. What is the
axial thrust if theblades experience a net thrust of 3500 N?
370. The solution of differential equation (D3 + D2 + 4D + 4)y = 0 is

371. A linear programming problem is given as follows:

The value of the auxiliary objective function given by the initial basic feasible solution is
_________.
372. 5 jobs A, B, C, D and E have arrived at one time to be processed on a single machine.
The processing time (in minutes) of each job are indicated below.

Assuming that no new jobs arrive thereafter and using SPT rule for optimal sequence, the
average in process inventory is __________ jobs
373. A workpiece of 150 cm length and 40 cm width is machined by planing operation with
a feed of 0.3 mm/stroke. The machine tool executes 10 double strokes/min. The planing time
for a single pass is ________min.
374. A block brake as shown in figure, provides a braking torque of 360 Nm. The diameter
of the brake drum is 300 mm. The coefficient of friction is 0.3. The force (P) to be applied at
the end of the lever for the clockwise and counter clockwise rotation of the brake drum
respectively is :

375. A beam AB supporting two concentrated load P as shown in figure has a rectangular
cross-section of width 100 mm and height 150 mm. The distance from each end of the beam
to the nearest load is 0.5 m. If the allowable stress in bending is 11 MPa (for both tension and
compression) and the allowable stress in horizontal shear is 1.2 MPa, then the maximum
permissible value of Pmax of the load is :

376. In a Whitworth quick return motion mechanism, the distance between the fixed
centres is 50 mm. The time taken by the cutting stroke is 2.735 times the time taken by the
return stroke. What is the length of the driving crank?

377. A four bar mechanism is shown in the figure below.

The velocity of point A and B are 3.14 m/s and 2.25 m/s respectively. If the efficiency of the
mechanism is 70 percent, the mechanical advantage is

378. A journal bearing of length 250 mm supports a turbine shaft of diameter 200 mm
running at 1200 rpm. The lubricant of viscosity 0.02 kg/ms removes heat at the rate of 70 J
per minute. If the coefficient of friction for the bearing is 0.01, the bearing can withstand a
maximum pressure of

379. A cantilever shaft l m long has a disc of mass W kg at its free end. The Young’s
modulus for the shaft material is E N/m2. The frequency of transverse vibrations of the shaft
is 1 Hz. Which of the following is the correct expression for diameter d of the shaft?

380. A circular rod of 25 mm diameter carries a pull along a line which is parallel to the
centroidal axis, but is displaced from it. If the maximum stress is 20% greater than the mean
stress on a section normal to the axis, then the distance of the line of pull from the centroidal
axis is:

381. A circular rod of 25 mm diameter carries a pull along a line which is parallel to the
centroidal axis, but is displaced from it. If the maximum stress is 20% greater than the mean
stress on a section normal to the axis, then the distance of the line of pull from the centroidal

axis is :

382. The specific internal energy of a certain fluid is related as follows:

A system composed of 2 kg of the above fluid expands in a frictionless piston and cylinder
machine from and initial state of 1 MPa, 100°C to a final temperature of 30°C. If there is no
heat transfer, what is the net work for the process ?

383. A particle moves on the curve x = 2t2, y = t2 – 4t, z = 3t – 5 where t denotes the time in
seconds then component of velocity and component of acceleration at time t = 1s in the
direction of i + 2j + 2k are respectively

384. It was found during a test in which water flowed with a velocity of 2 m/s through a
tube (2.5 cm inner diameter and 6 m long), that the head lost due to friction was 1.5 m of

water. The surface heat transfer coefficient based on Reynolds analogy is _____________
kW/m2K.
(Take ρ = 1000 kg/m3, g = 10 m/s2 and cp = 4 kJ/kgK)
385. Consider a water flow between two parallel fixed plates 50 mm apart, as shown in
figure. The velocity distribution for the flow is given by u(y) = 120(0.05y – y2)m/s where y is
in meters. The dynamic viscosity of water is 1.307 × 10–3 Ns/m2. The magnitude of the shear
stress acting on the bottom plate is ____________ N/m2.

386. A selective coating of black chrome is coated over a solar absorber plate. Incident
solar flux on the
whole plate is 1200 W/m2.
Properties of black chrome
Absorptivity = 0.95 for short wave
Emissivity = 0.05 for long wave
If the absorber plate is at a temperature of 127°C, the radiosity (in W/m2) from the absorber
plate is __________.

387. A steam turbine with a boiler efficiency of 90 percent and an overall thermal
efficiency of 36 percent gives a net electrical work of 1200 kJ per kg of steam flow rate. The
fuel cost per kWh generated in the power plant is Rs.0.85. The LCV and the cost of coal are
30000 kJ/kg and Rs.1500 per ton respectively. If 5% of steam generated is used to cover
losses, the specific steam consumption is __________ kg/ kWh.

388. Steam issues from the nozzle of an impulse turbine and impinges the blades with a
velocity of 520 m/s. The blade velocity is 300 m/s. The velocity coefficient for the blades is
0.8. The friction losses on the blades per kg of steam flow are 15 kJ. The nozzle angle (in
degrees) is ________.

389. In arc welding of a butt joint, the welding speed is to be selected such that highest
cooling rate is achieved. Melting efficiency and heat transfer efficiency are 0.5 and 0.7,
respectively. The area of the weld cross section is 5 mm² and the unit energy required to melt
the metal is 10 J/mm³. If the welding power is 2 kW, the welding speed will be __________
mm/s.

390. A room contains 35 kg of dry air and 0.5 kg of water vapour. The total pressure and
temperature of air in the room are 100 kPa and 25°C respectively. Given that the saturation
pressure for water at 25°C is 3.17 kPa, the relative humidity of the air in the room is
___________ %.

391. A dealer supplies the following information with regard to a product
Annual demand = 10000 units

Ordering cost = Rs. 10 per order

Inventory carrying cost = 20% of inventory value

Price = Rs. 20 per unit

Annual cost of back-ordering = 25% of inventory value

The maximum quantity of the product to be back-ordered is ___________.
392. The flow stress (in MPa) of a material is given by

σ = 500ε 0.1,

where ε is true strain. The Young’s modulus of elasticity of the material is 200 GPa. A block

of thickness 100 mm made of this material is compressed to 95 mm thickness and then the

load is removed. The final dimension of the block (in mm) is ____________.
393. If x, y and z respectively are in Arithmetic Progression with common difference d . If

the rank of matrix is 2, then the value of k is ________

394. The area bounded by curve y2 = 9x and line x – y + 2 = 0 is __________.

Which of the following is not a characterstic of climb milling (down milling) operation?

 Chip thickness is maximum at the end of the cut
395. A mild steel shaft of 50 mm diameter is subjected to a bending moment of 1.5 kNm

and a torque T. The yield point of steel in tension is 210 MPa. What is the maximum value of

torque without causing yielding of the shaft material according to maximum principal stress

theory?

Which of the following are the advantages of a V-belt drive?
1. It can be used with large centre distance.
2. It has lesser weight per unit length compared to flat belts.
3. It can be operated in either direction i.e. with tight side of the belt at the top or bottom.
4. It can provide high velocity ratio.
5. It provides negligible slip between the belt and the pulley.

 3, 4 and 5
396. A thin cylindrical steel shell of diameter 150 mm and wall thickness 3 mm has

hemispherical ends. What is the thickness of the hemispherical end? If there is no distortion

of the junction under pressure.

(Take modulus of elasticity = 200 GPa and Poisson’s ratio = 0.3)

397. Given below is the velocity triangle of a de Laval turbine with symmetrical blades.

Further it is given that the turbine dissipates no energy due to blade friction. For 900 kg of
steam flow per hour through the turbine, what is the tangential force (in N) on the blades?

398. If 1 and 3 are the eigen values of a 2 × 2 square matrix A, then A3 can be written as
(I2 denotes identity matrix of second order)

399. For where C is the circle x2 + y2 = 4. The value of f ′(i) is

400. A 1 m diameter steel pipe which is 10 m long lies in a room with its axis horizontal.

The ambient air is at a temperature of 17°C and the pipe surface is at 257°C. Assume

kinematic viscosity of air as 2 × 10–5 m2/s and Prandtl number as 0.8. The value of Rayleigh

number is __________ × 1010.

(Take g = 10 m/s2)

401. Water flows through a pipe of diameter 30 cm. The velocity V for the condition shown

in the figure below is _________ m/s.

402. The demand for a commodity is 900 units per day. Every time an order is placed, a
fixed cost of Rs. 500 is incurred. The holding cost is Rs. 0.10 per unit per day. If the lead
time is 15 days, the re-order point is _________ units.

403. The information regarding jobs to be scheduled through one machine is given below

Scheduling according to the slack time remaining, the mean flow time will be _________
days.

404. The ratio of time of return stroke to time of forward stroke of a shaping machine is
0.6. The stroke is 250 mm and it makes 60 double strokes per minute the velocity of cutting
is ____________ m/min.

405. Using direct extrusion process, a round billet of 150 mm length and 75 mm diameter
is extruded. Considering an ideal deformation process (no friction and no redundant work),
extrusion ratio 5, and average flow stress of material 350 MPa, the extrusion force (in MN)
on the ram will be __________.

406. In an arc welding of steel, voltage is 40 V and current is 400 A. The travel speed is 10
mm/s and crosssectional area of the joint is 25 mm2. Heat required to melt steel is 10 J/mm3.
If the heat transfer efficiency is 0.85, the melting efficiency will be____________percent

407. Two closely coiled helical springs ‘A’ and ‘B’ are equal in all respects but number of
turns of spring ‘A’ is half that of spring ‘B’, the ratio of deflections in spring ‘A’ to spring ‘B’
is ___________.

408. A domestic refrigerator is loaded with food and the door closed. During a certain
period the machine consumes 1 kWh of energy and the internal energy of the system drops
by 5000 kJ. The net heat transfer for the system is

409. A 120 mm wide uniform plate is subjected to a tensile load that has a maximum value
of 250 kN and a minimum value of 100 kN. The properties of the plate material are as
follows:
Endurance limit stress = 225 MPa
Yield point stress = 300 MPa
Assuming a factor of safety of 1.5, what is the thickness (in mm) of the plate for safe
continuous operation?

410. A single cylinder reciprocating engine has speed 480 rpm, stroke 600 mm, mass of
reciprocating parts 100 kg, mass of revolving parts at 300 mm radius is 65 kg. If two-third of
the reciprocating parts and all the revolving parts are to be balanced, the residual unbalanced
force when the crank has rotated 60° from inner dead centre is

411. An electric motor of mass 50 kg running at 1800 rpm is mounted on five springs, each
of stiffness 45 kN/m and with negligible damping. The mass of the motor is equally
distributed among the five springs. What is the isolation factor of the spring support ?

412. A steam boiler is to be designed for a working pressure of 2.5 MPa with its inside
diameter 1.5 m. Rivets of diameter 32 mm are used for longitudinal and circumferential
joints. What is the number of rivets required to provide enough strength to the
circumferential joint ? The working stresses for steel plates and rivets in shear and crushing
are 65 MPa and 120 MPa respectively.

413. A stepped steel shaft of length 1.5 m as shown in the figure, carries two flywheels A
and B of mass mA and mB and radius of gyration rA and rB respectively at each of its ends

What is the ratio d2 : d3 if the node is at a distance of 0.5 m from A?

414. A bar of steel 0.4 m long and 50 mm square is in compression under an axial load of
200 kN applied in the direction of its length. Find the change in length (in mm) and volume
(in mm3), if all the lateral strain in one direction is prevented by the application of a suitable

compressive stress.
[Take E = 200 GPa and μ = 0.25]

415. A hollow cast iron column whose outside diameter is 200 mm has a thickness of
20mm. It is 4.5 m long and is fixed at both ends. What will be the ratio of Euler’s to
Rankine’s critical load ?

416. Air enters a device at 4 MPa and 300°C with a velocity of 150 m/s. The inlet area is
10 cm2 and outlet area is 50 cm2. If the air exits at 0.4 MPa and 100°C, what is the outlet
velocity ?

417. The point in the plane 2x – y + 2z = 16 nearest to the origin is

418. A semi-infinite aluminium cylinder (thermal conductivity = 240 W/mK and thermal
diffusivity = 9.8 × 10–5 m2/s) is initially at a uniform temperature of 200°C. It is now placed
in water at 15°C where heat transfer takes place by convection with h = 120 W/m2K. The
value of Biot number is 0.08. Five minutes after the start of cooling, the Fourier number
value is __________.

419. Water flows through a pipe having an inner radius of 10 mm at the rate of 36 kg/hr at
25°C. The viscosity of water at 25°C is 0.001 kg/ms. The Reynolds number of the flow is
_______.

420. The inlet angle of runner blades of a Francis turbine is 90°. The blades are so shaped
that the tangential component of velocity at blade outlet is zero. The flow velocity remains
constant throughout the blade passage and is equal to half of the blade velocity at runner
inlet. The blade efficiency of the runner is ___________%.

421. A flat plate 1m × 1m is cooled by air at temperature 15°C flowing past it. The plate
surface maintained at a temperature of 75°C, loses heat at the rate of 880W to the
surrounding air. The Reynold’s number at a distance of 0.5 m from the plate is 106 and the
Prandtl number at mean film temperature is 0.7. The thermal conductivity of air is 0.02
W/mK. Assume the local Nusselt number at a distance L from the leading edge of the plate to
follow the relation

The value of A is ________ × 10–3.

422. A reciprocating compressor has bore equal to stroke and it run at a speed of 600 rpm.
Inlet air has temperature and pressure of 25°C and 100 kPa. The free air conditions are 105
kPa, 15°C and 8.564 m3/min. The volumetric efficiency of the compressor is 88 percent. The
crank radius is ______ cm.

423. A low carbon steel plates is to be welded by the manual metal arc welding process
using a linear V-I characteristics DC power source. The following data are available

The heat input into work piece will be ______________W.
424. Atmospheric air at a flow rate of 3 kg/s (on dry basis) enters a cooling and

dehumidifying coil with an enthalpy of 85 kJ/kg of dry air and a humidity ratio of 19
grams/kg of dry air. The air leaves the coil with an enthalpy of 43 kJ/kg of dry air and a
humidity ratio of 8 grams/kg of dry air. If the condensate water leaves the coil with an
enthalpy of 67 kJ/kg, the required cooling capacity of the coil is _______kW.
425. The past records at an emergency room of a hospital in a rural area indicate an average
of 10 arrivals per day. The demand for emergency room service is distributed according to
Poisson distribution. The probability of less than 3 arrivals is __________ percent.
426. An item is produced at the rate of 50 items per day. The demand occurs at the rate of
25 items per day. If the setup cost is Rs. 100 per setup and holding cost is Rs. 0.01 per unit of
item per day, the minimum total cost per run is Rs. __________.
427. An air standard Otto cycle develops maximum work and operates between 300 K and
1200 K as minimum and maximum temperatures respectively. The air standard efficiency of
cycle is ______%.
428. Maximum slope of the curve y = –x3 + 3x2 + 9x – 27 is _____.

429. The value of closed integral
around the hypocycloid x2/3 + y2/3 = a2/3 is _____.
The main process which takes place in a desert-cooler is

 adiabatic saturation

430. There are two columns, made of same material. Column 1 has minimum buckling load
of 100 N and slenderness ratio is 2. Column 2 has buckling load of 200 N. What will be the
slenderness ratio of column 2?
The term fully-developed laminar flow means that
the velocity profile does not change in the direction of flow

Which of the following cycle working with in same temperature limits has the highest
work ratio?

Rankine cycle

431. Heat is generated in a long 0.3 cm diameter cylindrical electric heater at a rate of 180
W/cm3 . The heat flux at the surface of heater in steady operation is ____________ W/cm2 .

432. An open U-tube containing water, mercury of specific gravity 13.6 is poured into one
of its limbs so that length of column of mercury is about 20 mm. The level of water column
in that limb is lowered by ____________ cm.

433. In a pert activity, the pessimistic, optimistic and most likely time to complete the
activity are 8 days, 4 days and 6 days respectively. The probablistic time to complete the
activity will be __________days

434. In a production or built up model of inventory control, production rate is 400 pieces
per day and demand rate is 300 pieces per day and ordering cost and holding cost are 200 Rs.
and 0.81 Rs. per day. The production factor for the given condition is ___________.

435. A parting tool has the back rake angle of 8°. The tool by mistake, was set 1.6 mm
above the line of centres while machining a job of 40 mm outside diameter. The effective
rake angle of the tool is __________ degree.

436. The diameter and rotational speed of a job are 80 mm and 480 rpm respectively. If
chatter frequency is 120 Hz, then the chatter mark are found at a spacing of __________
(degree) on the job surface.

437. A stepper motor working on a CNC machine has 120 steps. The output shaft of the
motor is directly coupled to a lead screw of pitch 10 mm, which drives a table. If the speed of
table is 60 mm/s. then the frequency of pulse supply to the motor is ____________ Hz.

438. The probability that A speaks truth is 4/5, while this probability for B is 3/5. The
probability that they contradict each other when asked to speak on a fact is ___________.

439. The value of integral The value of k is _____.

Consider the following statements:
edge angle.
1. Thrust force will increase with increase in side cutting edge angle.

2. Feed force will decrease with increase in side cutting

3. Radial force will increase with increase in side cutting edge angle.
1, 2 and 3

Consider the following statements:

1. A U-tube differential manometer is used upright if the pressure difference is small.
2. A U-tube differential manometer cannot be inclined at any angle.

3. A U-tube differential manometer is used inverted if the pressure difference is small.
4. A U-tube manometer cannot measure the vacuum pressure.

only 3 is correct

440. A single row deep groove ball bearing is subjected to radial load of 1500 N and axial

load of 1000 N. It has basic static load capacity = 7200 N and basic dynamic load capacity =

12000 N.

[Take, Radial factor, X = 0.56, Thrust factor, Y = 1.2 Rotation factor V = 1]

Rated life of the bearing is (in revolutions):

441. A structural member is designed by using total strain energy theory having maximum
shear strength (sys) is 100 MPa. Poission ratio is 0.3. For the respective theory shape of safe
boundaries is given below. What will be the length of major axis of the ellipse in MPa?

442. For the following loading condition

Determine value of σx and τxy in MPa?
443. Two gear wheels, each with 25 teeth of involute form and pressure angle of 20° are

required to give an arc of contact equal to 1.6 times the circular pitch. Find the addendum
required in terms of the circular pitch.
444. A single cylinder, four stroke IC engine rotating at 1000 rpm has crank length of 50
mm and a connecting rod length of 120 mm. If the effective mass of reciprocating parts of
engine is 1 kg. What is the approximate magnitude of the maximum shaking force created by
the engine?
445. A disc clutch with a single friction surface has coefficient of friction equal to 0.25.
The maximum pressure which can be imposed on the friction material is 2 MPa. The outer
diameter of the clutch plate is 250 mm and its internal diameter is 126 mm. Assign uniform
wear theory for the clutch plate, the maximum torque (in Nm) that can be transmitted is:

446. A refrigerator unit having a mass of 35 kg is to be supported on 3 springs, each having
a spring stiffness S. The unit operates at 480 rpm. What will be the value of stiffness ‘S’ if
only 10% of shaking force is allowed to be transmitted to the supporting structure ?

What will be the shape of elastic curve at section BC ? PARABOLIC
447. A straight bar of alloy [1 m × 12.5 mm × 4.8 mm] section is mounted on a strut testing

machine and loaded axially until it buckles. Estimate the maximum central deflection (in
mm) before material attains its yield point of 280 N/mm2.
(E = 72000 MPa. Neglect axial stress)
448. In a parallel flow heat exchanger, the inlet and outlet temperature of the hot fluid are
150°C and 90°C while that of the cold fluid are 30°C and 70°C respectively. For the same
overall heat transfer coefficient and heat transfer, the % decrease in the surface area of the
heat exchanger if counter flow arrangement is used is ___________ %.
449. For the system shown in Fig., if p1 = 60 kPa and V1 = 20 m/s, the downstream
pressure p2 is _____________ kPa.

Neglect losses. Assume pressure immediately after the pipe expansion is p1.
450. The discharge through a reaction radial flow turbine is reduced by 25% when

thickness of blade is taken into consideration as 15 mm. If diameter of the runner at inlet is
750 mm, then the number of blades on runner are ____________.
451. Solar radiations is incident on an opaque surface at a rate of 400 W/m2. The emissivity
of the surface is 0.65 and absorptivity to solar radiation is 0.85. The convection coefficient
between the surface and the environment at 25°C is 6 W/m2K. If the surface is exposed to
atmosphere with an effective sky temperature of 250 K. The equilibrium temp. of the surface
is ____________K.

452. The given figure shows an open cycle gas turbine employing reheat on T-S diagram.
Assuming that the specific heats are same for both air and gas and neglecting the increase in
mass flow rate due to addition of fuel, the efficiecy is ____________%.

453. For a gas power plant cycle temperature limits are 300 K and 1200 K respectively.
The compression ratio of the plant cycle corresponding to maximum work output will be
____________. Take γ = 1.4

454. A resistance-capacitance relaxation circuit is used in an electrical discharge machining
process. The capacitance in the circuit is 8 μF and the discharge voltage is 150 V. The spark
cycle time, at which the average input required is 1.2 kW, is _______________ μ sec.

455. A simple refrigeration cycle uses R–134a as the working fluid. The temperture of the
refrigerant in the evaporator is –10°C. The condensing temperature is 40°C. The cooling load
is 150 W and the volumetric efficiency of the compressor is 80%. The speed of compressor is
720 rpm. The displacement volume of the compressor is ____________ × 10–4 m3/s.
Properties of R–134a.

456. In a certain machining operation with a cutting speed of 50 m/min, tool life of 45
minutes was observed, when the cutting speed was increased to 100 m/min then tool life
decreased to 10 minutes. If the tool change time is 3 minutes, then the cutting speed for
maximum productivity is ____________ m/min.

457. A single cylinder, 4-stroke engine is fitted with a rope brake dynamometer. The
diameter of the brake wheel is 600 mm and the rope diameter is 25 mm. The dead weight on
the brake is 200 N and the spring balance reads 30 N. If the engine runs at 450 rpm, the brake
power of the engine is ______________ kW.

Consider the following statements:
1In grey cast iron, graphite exists in the form of flake.
2. When molten iron is cooled slowly with Mg, it becomes grey cast iron.
3. Ductile iron is formed when molten cast iron is cooled with Mg.

 1 and 3

Consider the following statements pertaining to a vapour compression type refrigerator:
1. The condenser rejects heat to the surroundings from the refrigerant.
2. The evaporator absorbs heat from the surroundings to be cooled.
3. Both the condenser and evaporator are heat exchanger with refrigerant as a common
medium.
4. The amount of heat exchanged in condenser and evaporator are equal under steady
conditions.
Which of the above statements are correct?

 1, 2 and 3

458. The bar given below is rotating at an angular velocity (ω0) = 10 rad/sec along vertical
centroidal axis and having angular retardation (α) of –1 rad/s2. Find the maximum stress
developed (kN/m2) on the bar at t = 3 s. (Neglect shear stress induced.)

459. For a given Whitworth quick return mechanism, length of crank and length of driving
crank are 30 cm and 75 cm respectively. What will be the quick return ratio for the given
construction?

Which of the following does not hold true for bending stress and shear stress?

 At extreme fibers bending stress in maximum and shear stress is zero.

 Bending stress acts perpendicular to cross section and shear stress acts parallel to cross-
section.

 At neutral axis both bending stress and shear stress are zero.

 Shape of bending stress distribution is independent of shape of cross-section but shear stress
distribution depends on cross-section.

In a hydrodynamic bearing, there is:

 boundary lubrication when the speed is very low or when the load is excessive

 no lubricant between the journal and the bearing

 a forced lubricant between the journal and the bearing

 All of the above

Measurement of velocity without any obstruction to the flow in a pipe may be made by

 laser-doppler anemometer

 hot-wire anemometer

 hot-film anemometer

 pitot-static probe

In a two stage gas turbine plant operating on a Brayton cycle with regeneration

 Work output increases but cycle efficiency decreases

 Work output decreases has but cycle efficiency remains unchanged

 Cycle efficiency increases but work output remain unchanged

 Both cycle efficiency and work output increases.

460. Heat is generated in a 10 cm diameter spherical radioactive material whose thermal
conductivity is 25 W/mK uniformly at a rate of 15 W/cm3. If the surface temperature of the
material is measured to be 120°C. The center temperature of the material during steady
operation is ____________°C.

461. The velocity of an airplane is measured with a pitot tube. If the pitot tube measures
800 mm of water, the speed of the airplane is ____________ m/s.
Take ρair = 1.23 kg/m3, g = 9.81 m/s2.

462. For a particular product in a company, the fixed cost is Rs. 10 and sales volume and
profits are Rs. 500 and Rs. 90 respectively. Now the owner of the company wants to increase
its profit by Rs. 60, then the needs of increase in sales volume Rs. ____________ .

463. The probability distribution for the sale of a product is as follows:

On the sale of an item the profit is Rs. 500. The expected profit is Rs. __________.

464. Ratio of lattice parameter (a) to atomic radius (r) for Gold is ____________.

465. In the orthogonal cutting, the depth of cut is 0.6 mm at a cutting speed of 3 m/s. If the
cutting speed is 8 m/s, then the depth of cut is ___________ mm. (Assume no side flow)

466. An aluminium billet of 220 mm diameter is extruded with an extrusion ratio 8. If the
effective flow stress in compression is 280 MPa. Then the ideal extrusion pressure (in MPa)
is ___________.

467. Given the matrix The sum of eigen values of 4A–1 + 3A + 2I is
___________.

468. The value of integral is __________ .

469. A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter
in which the pressure and temperature are found to be 0.1 MPa, 120°C. The quality of the
sample taken from the boiler is The properties of saturated steam at 3 MPa: hf = 1008.42
kJ/kg and hg = 2804.12 kJ/kg Superheated steam at 0.1 MPa and 120°C: h = 2716.28 kJ/kg

During ultrasonic machining, the metal removal rate is affected by the

 Hammering action of abrasive particles

 Rubbing action between tool and workpiece

 Low frequency of sound waves

 High frequency of eddy currents

470. A tube of mean diameter 5 cm and thickness 2 mm is made of mild steel with an
elastic limit of 250 N/mm2 under simple tension. Calculate the torque (N-m) which may be
transmitted by the tube with a factor of safety of 2.5 using maximum shear stress theory.

471. A structural member is designed by using von Mises theory, having maximum shear
strength (Sys) is 100 MPa. Poisson ratio is 0.3. Find the length of semi-major axis (MPa) of

ellipse given below.

472. The mechanism shown in figure is driven by turning A0A. Find out geometrically the
maximum transmission angle.

473. In a spring controlled governor, the controlling force curve is a straight line. The balls
are 400 mm apart when the controlling force is 1500 N and 240 mm when it is 800 N. The
mass of each ball is 10 kg. What will be the speed at which the governor runs when the balls
are 300 mm apart?

474. A pair of spur gears with 20°-full depth involute teeth consists of 20 teeth pinion
meshing with a 41 teeth gear. The module is 3 mm while the face width is 40 mm. The
material for pinion as well as gear is steel with an ultimate tensile strength of 500 N/mm2.
The gears are heat treated to a surface hardness of 350 BHN. What is the wear strength of the
gear design?

475. The successive amplitudes of vibrations of vibratory system as obtained under free
vibration are 0.69, 0.32, 0.19, 0.099 units respectively. Determine the damping ratio of the
system.

476. For the given loading condition, find the load P?

477. A composite bar is subjected to pure torsion as shown in figure. The torsional stiffness
(K) of two bars are 100 and 200 N. Find the torque induced in both the bars (in Nm)

478. Air flows through the supersonic adiabatic nozzle as shown in fig. The inlet conditions
are 7 kPa and 420°C. The nozzle exit diameter is adjusted such that the exiting velocity is
700 m/s. The exit diameter of the nozzle is

479. Air (cp = 1000 J/kgK) enters a 160 mm diameter and 19 m long underwater duct at
50°C and 1 atm at an average velocity of 7 m/s and is cooled by the water outside. If the
average heat transfer coefficient is 35 W/m2K and the tube temperature is nearly equal to
water temperature of 5°C, the exit temperature of air is ____________°C.

480. A reaction turbine, whose runner radii are ro = 300 mm and ri = 150 mm, operates
under the following conditions:

Assuming hydraulic efficiency is 100%, the head on the turbine is ____________ m.
(Take g = 9.81 m/s2)

481. In a flat plate, water with velocity 5 m/s and heat transfer coefficient of 1000 W/m 2K.
The Stanton number for the given flow will be ____________.

482. The isentropic heat drop in the nozzle of an impulse steam turbine with a nozzle
efficiency 0.8, blade velocity ratio 0.4 and mean blade velocity 150 m/s in kJ/kg is
____________.

483. For a increase in specific heats ratio of 10% in Brayton cycles the change in cycle
efficiency will be ____________%. Take pressure ratio 4, and initial specific heats ratio is
1.4.

484. A bar of 60 mm diameter is being cut orthogonally and is reduced to 54 mm by a
cutting tool. In a case, mean length of the chip is 57 mm. If the rake angle is 6°, shear angle
will be ___________ degree.

485. The data of heat load in a small restaurant is given:
Heat flow through walls, roof and floor = 22000 kJ/hr.
Solar heat gain through glass = 7000 kJ/hr
Equipment sensible heat gain = 10500 kJ/hr
Equipment latent heat gain = 2500 kJ/hr
The sensible heat factor of restaurant is ____________.

486. For a production and built-up model, the production rate and demand rate are 200 unit
per day and 100 unit/day, ordering/set up cost are Rs. 200 per batch and holding cost of
inventory is Rs. .81 per day. Now if the production rate becomes infinite, the variation in
economic lot quantity is __________ units.

487. During a steady state gas metal are welding with direct current electrode positive, the
welding current, voltage and welding speed are 150A, 30V, 6 m/min. A metallic wire
electrode of diameter 1.2 mm is being fed at a constant rate of 12 m/min. The density,
specific heat and melting temperature of the wire electrode are 7000 kg/m3, 500 J/kg, 1530
°C.Assuming ambient to be 30°C and neglect latent heat of melting, further consider that of
the total electrical power is available for melting. The melting efficiency of the wire electrode
(%) is _______________.

488. A large four-stroke cycle diesel engine runs at 2000 rpm. The engine has a
displacement of 25 litres and a brake mean effective pressure of 0.6 MN/m2. It consumes
0.018 kg/s of fuel (calorific value = 42000 kJ/kg). The thermal efficiency is ____________
%.

489. The value of integral

(Where R is the quadrant of the circle x2 + y2 = 4 with x ≥ 0, y ≥ 0)

An inverted U-tube manometer is more sensitive than an upright manometer because

the manometric liquid is lighter than the working liquids.

The entropy of fixed amount of an ideal gas

decreases in every isothermal compression

Edge dislocation is a

one dimensional defect

Which one of the following is correct? In a sensible cooling or heating process

The humidity ratio remains constant.

490. A circular disc rolls down without slip on an incline plane. The ratio of its rotational
kinetic energy to the total energy is

491. The sleeve and each rotating mass of a porter governor weigh respectively 200 N and
50 N. If the friction at the sleeve is 10 N, then coefficient of detention would be

492. Module and length of line of action of set of spur gear are 4 mm and 18 mm
respectively. If pressure angle is 20° then what will be the contact ratio of the gear ?

Select the correct statement:

where Cd,V, Cd,N and Cd,O are the coefficients of discharge for venturimeter, nozzle and
orificemeter respectively.

a

493. Consider an actual regenerative Rankine cycle with one open feed water heater. For
each kg of steam entering the turbine, m kg steam with specific enthalpy of h1 is bled from
the turbine. Specific enthalpy of water entering the heater is h2 . The specific enthalpy of
saturated liquid leaving the heater is equal to

494. The particular integral of the differential equation is

given by

495. Hot water flows through a PVC (K = 0.092 W/mk) pipe whose inner diameter is 2 cm

and outer diameter is 2.5 cm. The temperature of the interior surface of this pipe is 50°C and

the temperature of exterior surface is 20°C. The rate of heat transfer per unit of pipe length is

___________ W/m.

496. A 20 cm diameter pipe 30 km long transports oil from a tanker to the shore at 0.01

m3/s. The power required to maintain the flow is __________ kW.

Take μ = 0.1 Ns/m2 , ρ = 900 kg/m3 for the oil.

497. In a production system, the damage, handling, inspection, insurance, transportation

and interest cost are Rs.10, Rs. 50, Rs. 15, Rs. 20, Rs. 40 and Rs. 30 respectively. The total

holding cost will be (in Rs.)__________.

498. A sine bar has a length of 180 mm, each roller has a diameter of 12 mm during taper

angle measurement of a component. The height from the surface plate to the centre of a roller

is 80 mm. The calculated taper angle (in degree) is ___________.

499. It is required to reduce the 15 mm diameter of steel to 10 mm with a die. The semi die
angle is 7° and the coefficient of friction is 0.05. Mean flow stress is given as 600 MPa, then

the drawing stress would be ____________ MPa.
500. A steel rod 10 m long is at a temperature of 20°C. The rod is heated to a temperature

of 60°C. The stress induced in the rod if it is allowed to expand by 4 mm, is _______ MPa.
(E = 200 GPa, α = 12 × 10–6 per °C)

501. Consider an expression f (z) = The sum of residues of the function at its
poles is __________

502. A certain gas has cp = 0.914 kJ/kgK and cv = 0.653 kJ/kgK. The molecular weight of
the gas is

Which of the following is not correct for core design in casting?

 Dry strength of core should be enough to resist metal pressure

 Core sand should have high refractoriness

 Core sand should be of lower strength than the moulding sand

 Core sand should be of high permeability

Consider the following statements:
1. The diverging part of a venturimeter is shorter than the converging part.
2. The eddies formation in a flow nozzle is just downstream of the nozzle.
3. Movement of the float in rotameter enables its stability in vertical position.
4. The trajectory of a jet issuing from a nozzle is parabolic.
Of these statements:

 2, 3 and 4 are true
503. A bracket attached to a column by means of 4 identical rivets is subjected to an

eccentric force of 10 kN as shown below. If permissible shear stress is 60 MPa then, the

diameter of rivets will be:

504. A structural member during its functioning is subjected to maximum and minimum
principle stress of 200 MPa and – 100 MPa
E = 300 GPa
μ = 0.3
Find the volumetric strain energy per unit volume stored in the member in kN/m2 .

505. Assume a cylindrical shell with hemispherical ends having thickness ‘t1 ’ for
cylindrical part and thickness ‘t2 ’ for hemispherical ends. Assume internal diameters same
for both. Determine the value of (t1/t2) for no distortion of the juncture under pressure. Take μ
= 0.25.

506. Two standard full depth gears of pressure angle 14.5° have a module of 5 mm. The
pinion has 15 teeth while the gear has 60 teeth. If the addendum of the gear is equal to the
module.To what value should be the pressure angle be increased in order to eliminate the
interference?

507. A cylinder of diameter 10 mm and mass 2 kg floats vertically in a liquid of mass
density 900 kg/m3 as shown in figure. It is depressed slightly and released. The period of its
oscillation will be, if specific gravity is 1.2.

508. The load on the journal bearing is 180 kN due to turbine shaft of 400 mm diameter
running at 1500 rpm. If the bearing temperature is 60°C and viscosity of the oil at 60°C is
0.02 kg/m-s and the bearing clearance is 0.25 mm then the amount of heat to be removed by
the bearing is:

[Allowable bearing pressure = 1.6 MPa]

509. A machine is coupled to a power source. The machine requires constant torque but
torque supplied by the power source is (1000 + 300 sin θ) N-m. Mass moment of inertia of
the flywheel is 200 kg-m2. What is the maximum angular acceleration of the flywheel and at
what position does it occur?

510. Find deflection at point D:

511. A horizontal beam 10 m long simply supported at its end carries a load which varies
uniformly from 10 N/m at one end to 50 N/m at the other end. Find the distance from the left
at which bending moment would be maximum

512. Assuming air as an ideal gas, the heat transfer from the system is
513. The area bounded by the parabola y = x2 and the line y = 2x + 3 in first quadrant is
514. The engine oil at 150°C is cooled at 80°C in a parallel flow heat exchanger by water

entering at 25°C and leaving at 60°C. The heat exchanger effectiveness will be
___________.
515. The venturimeter shown reduces the pipe diameter from 10 cm to a minimum of 5 cm.
Assuming ideal conditions, the mass flow rate is __________ kg/s.

516. High-speed air jets strike the blades of a turbine rotor tangentially while the 1.5 m
diameter rotor rotates at 140 rad/s as shown in Fig. There are 10 such 4 cm diameter jets. The
maximum power output is ________ kW. Take density of air is 2.4 kg/m3 .

517. A 12 mm diameter mild steel sphere (K = 4.25 W/mk) is exposed to cooling airflow at
27°C resulting in the convective coefficient h = 114 w/m2 k. The time required to cool the
sphere from 540°C to 95°C is ___________ sec. Use ρ = 7850 kg/m3; α = 0.043 m2/hr

518. For a reciprocating compressor, swept volume is 1000 ml and compression ratio is 6
and pressure ratio is 4. The volumetric efficiency or the compressor will be ___________%.
Assume polytropic index 1.3

519. For the given diagram of Brayton cycle

Assume specific heat of air and gas are equal. The efficiency of the cycle will be
___________.
520. A drilling machine is provided with minimum spindle speed 35 rpm and maximum
spindle speed of 300 rpm. If number of speed is 6, then the 3rd spindle speeds that are likely
to be available on the machine will be _____________ rpm.

521. Moist air is heated by steam condensing inside the tubes of heating coil as shown in
Fig. Part of the air passes through the coil and part is by-passed around the coil. The air
which by-pass the coil is _________ kg/min.

522. In a manufacturing plant of Honda Activa, the various work stations and their total
task time are given below:

The ratio of balance delay (%) and line efficiency (%) is ___________..

523. In a work measurement trial process 100 observations were made, and in this
preliminary study 25 observations showed be machines to be idle. The no. of random
observations required for 95% of confidence level and +5% accuracy are _________. Take
(Z = 2 for 95% accuracy level) Z = standard normal variate

524. An orthogonal cutting operation is being carried out and has the following condition, t
= 0.18 mm, tc = 0.32 mm, width of cut = 5 mm, cutting speed, v = 2.5 m/s, rake angle, α =
10°, cutting force, Fc = 500 N and thrust force, Ft = 150 N. The percentage of total energy
that is dissipated in the shear plane would be _________.

525. A spark ignition engine has a compression ratio of 8 and the specific volume before
compression is 0.9 m3/kg. Net heat interaction per cycle is 1575 kJ/kg. The mean effective
pressure (in bar) is __________.

526. A numerical solution of the equation can be obtained using Newton-

Raphson method. If the starting value is x = 2 for the iteration, then the value of x after two

successive iterations is equal to __________.

527. In estimating the number of bricks in a pile, which is measured to be (5 m × 10 m × 5
m), count of bricks is taken as 100 bricks per m3. If the tape is stretched 2% beyond its
standard length, then the error in total cost will be Rs. __________.
[The cost of bricks in Rs. 2000 per thousand bricks].

In a real gas equation pv = zRT, depending on the values of pressure and temperature of the
real gas, the value of z

may be less than one, may be greater than one or equal to one

528. If the maximum and minimum resultant forces of the two force acting on a particle are
40 kN and 10 kN respectively, then the two forces would be

Match List-I (Chemical formula of refrigerant) with List-II (Numerical designation)
and select the correct answer using the codes given below the lists:

List-I List-II
A. NH3 1. 12
B. CCl2F2 2. 22
C. CHClF2 3. 40
D. C2F3Cl3 4. 113
5. 717

5124
Consider the following statement about theory of failure are correct.

1. Mohr’s theory is used for brittle materials.
2. Graphical representation of maximum shear stress theory is of hexagonal type.
3. In pure shear condition, maximum shear stress theory is uneconomical.
4. Maximum principle stress theory is used for brittle material.

1, 2, 3 and 4