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
ISRO Scientist or Engineer Mechanical 2009
For the following questions answer them individually
If the stream function is given by $$\psi = 3xy,$$ then the velocity at a point (2,3) will be
The correct sequence of the centrifugal pump components through which the fluid flows is
The relation $$pV^\gamma$$ = constant, where $$\gamma$$ is the ratio of the specific heats of ideal gas, is applicable to
Across a normal shock
A necessary precaution in selection of pumps for parallel operations is that
A metallic cube of side 10 cm, density 6.8 gm/cc is floating in liquid mercury (density 13.6gm/cc), with 5 cm height of cube exposed above the mercury level. Water (density 1 gm/cc) is filled over this, to submerge the cube fully. The new height of cube exposed above mercury level is
The pressure drop for a relatively low Reynolds number flow in a 600 mm, 30 m long pipeline is 70kPa. Whatis the wall shear stress?
The radiative heat transfer rate per unit area (W/m2) between two plane parallel grey surfaces (emissivily 0.9) maintained at 400 K and 300 K is (Stefan Bottzman constant $$\sigma = 5.67 \times 10^6 W/m^2 K^4$$)
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
The transition Reynolds number for flow over a flat plate is $$ 5 * 10^5.$$ What is the distance from the leading edge at which transition will occur for flow of water with a uniform velocity of 1m/s? (For water, the kinematic viscosity, $$v = 0.86 * 10^{-6} m^2/s)$$
For a reciprocating water pump having cylinder dia d and crank radius r, if W is the weight of water lifted, the coefficient of discharge is
Both free vortex and forced vortex can be expressed mathematically in terms of tangential velocity V at the corresponding radius r. Choose the correct combination
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 single-stage impulse turbine with a diameter of 120 cm runs at 3000 rpm. If the blade speed ratio is 0.42, then, the inlet velocity of steam will be
The critical point and triple point data for water are, $$T_c = 374^\circ C, P_c = 22.1 Mpa, T_T = 0.01^\circ C, P_T = 0.6 kPa$$ Indicate the phase change that will occur in following cases,
(i)Ice at 0.5 kPa is heated isobarically
(ii) Water vapour at $$400^\circ C$$ is compressed isothermally
The ratio of specific heats of a gas is 1.4 and the value of specific heat at constant pressure is $$7.0 cal/mole^\circ C$$. The difference between specific heat at constant pressure and specific heat at constant volume will be $$(in cal /mole^\circ C)$$
The coefficient of linear expansion of a solid is L. The volume V of a cube of this solid on being heated by $$1^\circ C$$ will change by
Two springs of equal length but having stiffness of 10 N/mm and 15 N/mm support a mass of 2 tonnes in series. Find the frequency of vibration
Ratio of pitch circle diameter in millimeters to the number of teeth, is known as
Two particles with masses in the ratio 1:4 are moving with equal kinetic energies. The magnitude of their linear momentums will conform to the ratio
Whichof the following stresses are associated with the tightening of a nut on a stud?
1. Tensile stresses due to stretching of stud
2. Bending stresses of stud
3. Transverse shear stresses across threads
4. Torsional shear stresses in threads due to frictional resistance
Select the correct answer using the codes given below:
A flywheel weighs $$\frac{981}{\pi}kg$$ and has a radius of gyration of 100 cm. It is given a spin of 100 rpm aboutits horizontal axis. The whole assembly is rotating abouta vertical axis at 6 rad/sec. The gyroscopic couple experienced will be
Determine the diameter of solid shaft which will transmit 90kw at 160 rpm, if the shear stress in the shaft is limited to $$60 N/mm^2$$.
A roller of weight W is rolled over the wooden block shown in the given figure. The pull required just to cause the said motion is
For one-dimensional isentropic flow in a diverging passage,if the initial static pressure is $$P_1$$), and the initial Mach numberis $$M_1 (M_1 < 1),$$ then for the downstream flow
Ina furnace madeof bricks,
Inside heat transfer coefficient = $$35 W/m^2 K$$
Outside heattransfér coefficient = $$25 W/m^2 K $$
Thermal conductivity of bricks (15 cm thick) = $$0. 15 W/m K$$
The overall heat transfer coefficient $$(in W/m^2 K)$$ will be closer to the
Two systems have the same wet bulb temperature of $$20^\circ C.$$ System ‘A’ has Dry bulb temperature of $$25^\circ C$$ since it has a relative humidity of 65%. System ‘B’ has a relative humidity of 30%. What will be its dry bulb temperature
Four rods with different radii r and length l are connected to two reservoirs at different temperature. Which one of them will conduct most heat?
A 1000 kg vehicle travelling at 80 m/s impacts a plunger attached to a piston-cylinder arrangement.If all of the energy of the vehicle is absorbed by the 20 kg of liquid contained in the cylinder, what is the maximum tempcrature rise of the liquid? (The specific heat of the liquid is $$4.0 kJ/kg.^\circ C)$$
In the Van der Waal’s gas equation $$\left(p + \frac{a}{v^2}\right) (v - b) =RT$$ the constant ‘a’ is introduced to compensate for
The centrifugal tension in belts
In nodular iron, graphite is in the form of
Corrosion resistance of steel increases by addition of
Phenomenon of progressive extension of material with time at constant load is called
Rivets are made of
Addition of copper to aluminium results in
A Hooke’s joint is used to connect two
Ina hardness test, L is load in kg, D is diameter of ball in mm and d is diameter of indentation in mm. Brinell Hardness Numberis expressed by the equation
Circumferential and longitudinal strains in the cylindrical boiler under internal steam pressure are $$\epsilon_1 and \epsilon_2$$ respectively. Change in the volumeof the boiler cylinder per unit volumewill be
An overhung beam ABC of length 4m is supported at A and B 3m apart. It is loaded with UDL of 5 KN/m along its entire length. Find the value of load ‘P’ at C such that the reactions at A and B are equal and opposite.
If two gears have moment of inertias as $$I_1$$ and $$I_2$$ respectively and mesh with a speed ratio $$\frac{\omega_2}{\omega_1} = n,$$ then equivalent momentof inertia of both gears referred to first one is
A uniform circular ring of mass M and radius r is rotating with an angular speed $$\omega$$ about an axis passing through its center and perpendicular to the plane of the ring.Two identical beads, each of mass m, somehow get attached at two diametrically opposite points. The rotational speed of the ring will become
An electric lift is moving downward with an acceleration of g/3. the vertical force between a passenger in the lift and its floor is equal to
A body of mass 10kg moving with a velocity of 1 m/s is acted upon by a force of 50 N for two seconds. The final velocity of the body is
Proof resilience may be defined as
A plane intersects the co-ordinate axes at $$x = \frac{2}{3}, y =\frac{1}{3}, z = \frac{1}{2}.$$ Whatis the Miller index of this plane?
Relationship between modulus of elasticity E, modulus of rigidity G and Poisson’s ratio $$\mu$$ is
A bar of Length L, area A and Young’s modulus E is subjected to a pulling force P.The strain energy stored in the bar is
What is the expression for crippling load for a column of length L, with one end fixed and other end free?
A Mohr’s circle reduces to a point when the body is subjected to
Power screws are used to convert
Following gases are used in tungsten inert gas welding
The force required to punch a 25 mm hole ina mild steel plate 10 mm thick, when ultimate shear stress ofthe plate is $$500 N/mm^2$$ will be nearly
One-half length of 50mm diameter steel rod is solid while the remaining half is hollow having a bore of 5mm. The rod is subjected to equal and opposite torque at its ends. If the maximum shear stress in solid portion is $$\tau$$ the maximum shear stress in the hollow portion is:
Two metal plates of thickness ‘t’ & width ‘w' are joined by fillet weld of $$45^\circ$$ as shown in fig. When subjected to a pulling force 'F' the stress induced in the weld will be
Ring rolling is used
A barof 20mm dia is tested in tension. It is observed that when a load of 38KN is applied the extension measured over a gauge length of 200mm is 0.12mm and contraction in diameter is 0.0036mm. Find the Poisson’s ratio
A perfect frame has N joints. The numberof members should not be less than
A cantilever beam of rectangul arcross section is subjected to load at free end. If the depth of the beam is doubled and load is halved , deflection of the free end as compared to original will be
The kinematic planar chain shown in the given figure is a
The machining process in which the work picce is dissolved into an electrolyte solution is called
In the metal forming process, the stresses encountered are |
A grinding wheel is specified as 49 A 26 36 M 7 V 24. The number36 stands for
In a fluid machinery, the relationship between saturation temperature and pressure decides the process of
Anodising is
The process layout is best suited where
The blank size of the gear of 3 mm module and 40 number of teeth is
A bag contains 7 white, 6 red and 9 black balls. Two balls are drawn at random. The probability that both the balls will be black is
Match list - I (Machining Process) with list —II (Associated medium) and select the correct answer using the codes given below the lists
The rake angle of a cutting tool is $$15^\circ$$, shear angle $$45^\circ$$ and cutting velocity 35 m/min. Whatis the velocity of chip along the tool face?
The value of the determinant given below is
The locus of the point Z satisfying the condition $$arg \frac{z - 1}{z + 1} = \frac {\pi}{3}$$ is
In a simple micrometer with screw pitch 0.5 mm and divisions on thimble 50, the reading corresponding to 5 divisions on barrel and 12 divisions on thimble is
It is required to cut screw threads of 2mm pitch on a lathe. The lead screw has a pitch of 6 mm. If the spindle speed is 60 rpm, then the speed of the lead screw will be
If $$u = \log(\tan x + \tan y),$$ then $$\sin 2x \frac{\partial u}{\partial x} + \sin 2y \frac{\partial u}{\partial y}$$ is
The value of $$\lambda$$ for which the equations $$2 \lambda x - 3y + \lambda - 3 = 0, 3x - 2y + 1 = 0$$ and $$4x - \lambda y + 2 = 0$$ are consistent is
If $$\overline{a} + \overline{b} + \overline{c} = 0$$ and $$|\overline{a}| = 3, |\overline{b}| = 5, |\overline{c}| = 7,$$ then the angle between $$\overline{a}$$ and $$\overline{b}$$ is
The image of the point P(1,3,4) in the plane 2x - y + z = -3 is
Find a particular integral of the differential equation $$(D^2 - 4D + 3)y = \sin 3x \cos 2x$$
