Mechanical Engineering Questions and Answers June 17, 2021

The Internal and external chameker of the impeller of a centrifugal pump are 200mm and 400mm respectively. The qump is running at 1200 rpm. The vone ongles of the impeller at Inlet and outlet are 20 30 lespectively The wakey enters the impeller and velocity of flow is Contant. determine the work chone by the impeller perumit weight of waker.

A single-acting reciprocating pump running at 50 rpm (N) delivers 0.01 m 3 /s of water (Q a ). The diameter of the piston (d) is 200 mm and the stroke length (L) is 400 mm. Determine 1) Theoretical discharge of the pump 2) coefficient of discharge 3) slip and percentage of slip of the pump

Amild steel shaft transmits 15 kW at 210r.p.m It is supported on two bearings 750 mm apart and has two gears keyed to it. The pinion having 24 teeth of 6 mm module is located 100 mm to the left of the right hand bearing and delivers the power horizontally to the right. The gear having 80 teeth of 6 mm module is located 15 mm to the right of the

What are the key considerations and challenges in designing a high-efficiency, compact cooling system for an automotive engine?

Calculate the final velocity right after a 115kg rugby player who is initially running at 7.35 ms collides headon with a padded goalpost and experiences a backward force of 1.81 x 104 N for 5.50 x 102 s.

1.00 kg of liquid water at 20.0 C is converted to superheated steam at 1200 C in a boiler operating at a constant pressure of 5.00 MPa. Using the temperature dependent heat capacity formula, how much heat is needed (kJkg) Using the steam tables, how much heat is needed (kJkg)

What are the different types of gate valves?

What is meant by pitting?

Can you name the alloy of tin and lead?

How will thickness affect a beam?

Why are cylinder head bolts tightened to a specific torque?

What are the differences between a car engine and a gas turbine engine?

What makes Japanese engines so reliable?

A concrete duct is being designed and optimised for transportation of water, with the configuration shown in Figure.1a. During operation, all external faces are exposed to a constant heat flux of 1000 Wm and water flows through two internal passages. The bulk temperature of water is assumed constant at 5C and flow conditions induce a convective

A helical compression spring has a scale of 400lbs/in, an inside diameter of 2.25 inches, a free length of 8 inches, and squared and ground ends. The material is to be chrome vanadium steel. For a load, P, of 750 pounds and for average service, determine: 1. Standard-size wire diameter. 2. Number of active coils. 3. The solid height. 4. The stress

The magnitude of force P is 1200 lb. If the force P is resolved into the directions of P. and P. the magnitude of the force component in the P, direction is most nearest (Assume that P, is normal to P) T A 299 lb B. 246 lb C. 983 lb D. 99 lb 2933

The horizontal shaft shown in the figure carries two belt pulleys (smaller radius is 80mm, bigger radius is 150 mm) and transmits a power P 250W at the rotational speed of 1989 rpm. The yield strength of the material is 325 MPa. Determine the diameter of the shaft with a factor of safety 5,0. the angle 0 45 300 mm 250 mm 200 mm 65 N 80 mm 80 N

Consider our executive jet, weighing W 9508 N Wing area Sw3,6 m, Thrust is T11322 N The polar is CD 0,016 0,05CL. Air density 1,2 kgm3 Find the max rate of climb in msec Round your answer to one decimal digit .

Nonlegume vegetable wastes have a moisture content of 80 and are 4 N (on a dry mass basis). The vegetable wastes are to be composted with readily available sawdust. The sawdust has a moisture content of 50 and is 0.1 N (on a dry mass basis). The desired CN ratio for the mixture is 20. The CN ratio for vegetable wastes is 11, and the CN ratio for

a) A pistonandcylinder device contains an ideal gas at 20 bar and 25 C. The piston has a mass of 300 kg and a crosssectional area of 0.05 m and moves within the cylinder without any friction. The initial volume of the gas in the cylinder is 0.03 m, the piston is initially held in place by a pin, and the external pressure on the piston and cylinder

The solid rays can be made of Aluminum or carbon fiber material. Each ray has a of length L 200 mm and diameter of d 3 mm. Assume that the fin membrane exerts a load on the ray as shown in below in Figure 3. The load consists of a distributed force of uniform intensity f 5 Nm and a distributed moment that is linear decreasing from a max value of

A lifting hook is shown in right Figure. The thread at the end of the hook is loose thread M30(d27.835mm), yield stress of the bolt o360Mpa,assume that safety factor n1.3.Try to calculate the maximum tensile force F that the bolt can withstand. F

1 Let w f(z) z 3z. Find u and u and calculate the value of fat z 1 3i. Let w f(2) 2iz 6z. Find u and u and the value of fat z 4i. values at the given point z. Find Ref, and Im f and their f(z) 5z 12z 3 2i at 4 f(z) 1(1z) at 1 i f(z) (22)(z 2) at 8i 3i

The metal industry is designing a reactor for a chemical process. The reactor requires a certain amount of reactant A, which is supplied in barrels. Each barrel contains 200 liters of reactant A. The reactor needs to be filled with 5,000 liters of reactant A. How many barrels of reactant A are needed to fill the reactor completely?

Question In the BETT theory of colloids, a certain colloid system exhibits monolayer adsorption of gas molecules on the surface of the colloidal particles. The BETT equation used to describe this adsorption phenomenon is given by (P.P) (1C)(C) K(PP) where C is the fraction of the surface covered by gas molecules, P is the equilibrium pressure of

A combined cycle power plant has a total net power output of 286 MW. Air enters the compressor of the Brayton cycle at 100 KPa and 290 K, where it is compressed to 2140 kPa with a compressor that has an efficiency of 88. The air is burned with methane, which enters at 298 K, in an adiabatic combustor and the temperature exiting the combustor is

Calculate the maximum input voltage (Vi) of the given amplifier circuit. Vt2 V, K0.2 AV2 gm20 mS, rd10K, R110 2 R220 Q V112 V Vi VI www V1 R1 R1 H R2 Vo L

Here are some important interview questions and answers for mechanical engineering: 1. Question: What is the first law of thermodynamics? Explain its significance in mechanical engineering. 2. Question: Can you explain the concept of stress and strain? 3. Question: What is the difference between heat transfer by conduction, convection, and

An automobile is modeled as a 1000-kg mass supported by a spring of stiffness k = 400,000 N/m. When it oscillates it does so with a maximum deflection of 10 cm. When loaded with passengers, the mass increases to as much as 1300 kg. Calculate the change in frequency, velocity amplitude, and acceleration amplitude if the maximum deflection remains

Question A multiple effect evaporator system consists of three evaporator units in series. The feed solution enters the first evaporator with a flow rate of 10,000 kghr and a concentration of 5 solute. Each evaporator operates at a vacuum pressure of 60 kPa. The steam used in the first effect has a temperature of 130C and a pressure of 300 kPa.

In a crystal lattice, a certain material has a vacancy concentration of 1.5 x 10^(-4) vacancies per atom. If the material has an atomic density of 5 x 10^28 atoms/m^3, calculate the total number of vacancies in a cubic meter of the material.

Question In a CSTR, a chemical reaction is taking place at a constant temperature of 60C. The reaction follows a secondorder kinetics with a rate constant of 0.05 Lmolmin. If the initial concentration of the reactant is 0.2 molL and the reactor volume is 10 L, calculate the time required to achieve 90 conversion of the reactant.

Question Water flows through a pipe with a diameter of 0.1 meters at a velocity of 2 meters per second. The kinematic viscosity of water is 1 x 10(6) m2s. Calculate the Reynolds number for this flow.

A heat pump operates between the temperature range of 850 K and 400 K .Find the COP(Coefficient of Performance) of heat pump.

A car travels a distance of 150 meters in 20 seconds. Calculate the velocity of the car.

Differentiate between a jig and fixture ?

Solve f(x)sinx2, f(0)2 ve f(0) 2 ise f(z) f(x)(3) In 3. f(0) ise f(x) (1

What is fluid mechanism? Explain briefly.

An engine mounted on a ship has a thermal efficiency 80 of that of the corresponding Carnot cycle. The engine receives heat from sea at 300 K and rejects heat to atmosphere at 280 K. The work output from the engine is dissipated through an agitator to heat 500 kg of sea water to 355 K. What quantity of heat must be extracted from sea water to

A 1200 kg car traveling at 15 m/s in the x direction collides with a 2500 kg truck traveling at 20 m/s in the y direction. The car and truck stick together and slide off the road. a) Is this an elastic or an inelastic collision? b) What is the speed of the combined wreckage after the collision?

A silicon PIN junction has the doping profile shown in Figure P7.34. The I corresponds to an ideal intrinsic region in which there is no impurity doping concentration. A reversebiased voltage is applied to the PIN junction so that the total depletion width extends from 2 um to 2 um. (a) Using Poissons equation, calculate the magnitude of the

A spherical tablet loaded with medication is being tested for slow drug release. The tablet is held stationary in a moving fluid that stimulates blood flow. The Sherwood number for a laminar flow around the stationary sphere in liquid is Sh KL D DAB (4.0 1.21. (ReSc)23)12 where K is the convective mass transfer in liquid cms, and D the diameter

A Utube manometer containing a light oil (specific gravity 0.7) is used to measure the static pressure of air (density 1.2 kgm) in a container. If the gauge pressure is 206 Nm, what is the indicated height of oil

From the figure shown below, calculate the following a. total length of the circular arc segment and the straight lines b. location of the centroid with respect to the xaxis Y 0.5 m 0.8 m R0.6 m 0.2 m By using a Cartesian plane, the area is bounded by the curve y24x, x40, and xaxis. a. by revolving the area at x40 it creates a solid of revolution,

Will renewable energy create jobs?

A power plant producing 120 MW of electricity has steam condition at boiler outlet as 100 bar, 500 C and the condenser pressure is 0.1 bar. The boiler efficiency is 90. The boiler consumes coal of calorific value 25.7 MIkg. The feedwater temperature at boiler inlet is 160 C. The steam generator has risers in the furnace wall 40 m high and unheated

How can renewable energy help climate change?

Which type of valve should be used when a precise, low flow is required?

Ideal gases and its various process ? Full explanation

Full explanation of Thermodynamics 1st law and all the consequences of the first law?

.. Determine the minimum cylinder mass m1 required to cause loss of contact at A. A T 30 2L3 100 mm m L3 The chain binder is used to secure loads of logs, lumber, pipe, and the like. If the tension T, is 2 kN when 0 30, determine the force P required on the lever and the corresponding tension T for this position. Assume that the surface under A

A faucet is shown on the figure below. A force of P 1100 lb is exerted at both ends of the faucet as shown. Determine the least possible diameter (in inches) of the faucet shaft such that the shear stress experienced shall not exceed 4.5 ksi. Let c 5.0 in. Express your answers in 2 decimal places. P A fcd pc d P B

A smooth thrust bearing at A and a smooth journal bearing at B were used to support the shaft have an outer radius of 65 mm. If the shaft is made from steel having an allowable normal stress of 115 MPa and allowable shear stress of 55 MPa, determine the maximum allowable force P that can be applied to the shaft. The thickness of the shafts wall is

Explain the physics of cavitation in pumps from the fluid mechanics, write in Chicago style and give the references.

Problem 5 Find the velocity with which a particle must be projected along the interior of a smooth vertical hoop of radius a from the lowest point in order that it may leave the hoop at an angular distance of 30 from the vertical. Show that it will strike the hoop again at an extremity of the horizontal diameter.

Problem 10 A particle is projected along the inside of a smooth vertical circle of radius a from the lowest point. Show that the velocity of projection required in order that after leaving the circle, the particle may pass through the centre is (ag)(3 (31). (Kumaun 2006)

Write the equations of motion of a pendulum consisting of a thin, 2 kg stick of length suspended from a pivot. How long should the rod be in order for the period to be exactly 1 sec (The inertia I of a thin stick about an end point is Why do you think grandfather clocks are typically about 6 ft high ml Assume that is small enough that sin) 0.)

A new scale N of temperature is divided in such a way that the freezing point of ice is 100N and the boiling point is 400N. What is the temperature reading on this uzew scale when the temperature is 150C? At what temperature both the Celsius and the new temperature scale reading would be the same?

Q: What is viscosity in fluid mechanics? Q: What is Pascal's law? Q: Define Reynolds number. Q: What is Bernoulli's equation? Q: How is the coefficient of viscosity different from the kinematic viscosity? Q: What is the difference between laminar flow and turbulent flow? Q: Explain the concept of buoyancy.

The axle shown above is to be designed to have the same diameter. Using the design process, provide complete specification for: a. steel axle and b. for cast iron axle

N 1.25in dia. Gear A 20in dia. FA 300 lbf. 16 in 20 A 14 in Cae Gear B 8in dia. 9 in X FB 20

A wall is constructed of several layers. The first layer consists of masonry brick 20 cm. thick of thermal conductivity 0.66 W/mK, the second layer consists of 3 cm thick mortar of thermal conductivity 0.6 W/mK, the third layer consists of 8 cm thick lime stone of thermal conductivity 0.58 W/mK and the outer layer consists of 1.2 cm thick plaster

5.27 Determine (a) the magnitude of the upward force P for which the maximum absolute value of the bending moment in the beam is as small as possible, (b) the corresponding maximum normal stress due to bending. (Hint Drew the bending moment diagram and the equate the absolute values of the largest positive and negative bending moments

Problem 1.24 Material description of an 3.0 1.00 0.75 2.5 0.50 0.25 0.00 2.0 axisymmetric stagnation point flow 2 1.0 1.5 2.0 2.5 The motion of a fluid is described in 3.0 material coordinates by I1 1 et, 2 et, I3 3e2at with given a const and z(t 0). I2 a) Calculate the velocity and acceleration components u(E, t) and b (, t) in material

Leverage your expertise in water treatment and mechanical engineering to develop a practical and scalable solution that addresses water scarcity challenges faced by small farmers. Build a small scale prototype to address the water access and quality problem in agriculture internationally, as well as a video outlining the issue, and your proposed

. A furnace wall made up of 7.5 cm of fire plate and 0.65 cm of mild steel plate. Inside surface exposed to hot gas at 650C and outside air temperature 27C. The convective heat transfer co-efficient for inner side is 60 W/m2K. The convective heat transfer co- efficient for outer side is 8W/m2K. Calculate the heat lost per square meter area of the

Iso-octane (C,H,) is supplied to a four-cylinder spark-ignition engine at 2 g/s. Calculate the air-flow rate for stoichiometric combustion. If the engine is operating at 1500 rev/min, estimate the mass of fuel and air entering each cylinder per cycle. The engine displaced volume is 2.4 liters. What is the volumetric efficiency? Density of air is

The power required while turning mild steel rod is found to be 0.1 kW/cm3 /min. The maximum power available at the machine spindle is 4kW. Assuming a cutting speed of 38 m/min and feed rate 0.32 mm/rev. Calculate (i) Maximum metal removal (ii) Depth of cut. (iii) Cutting force. (iv) Normal pressure on the chip.

A diesel engine consumes fuel at the rate of 5.5 gm/sec. and develops a power of 75 kW. If the mechanical efficiency is 85%, Calculate bsfc and isfc. The lower heating value of the fuel is 44 MJ/kg.

A mild steel plate of 0.5 cm thickness is to be cut along its length of 2m with a shearing machine. The annealed UTS of material is 450 MP, a) Calculate the shearing force (in ton force) for cutting with parallel blades. b) Calculate the shearing force (in ton force) of a 6 blade angle.

Fuel injection in single cylinder, 4 stroke cycle C.l engine running at 650rp.m takes place through a single orfice nozzle and occupies28 of crank travel. The fuel consumption of the engine 2.2 kg /hour and the fuel used has a specific gravity of 0.875. If injection pressure is 150 bar and the combustion chamber pressure 32bar estimate the volume

What is stress and example?

What is a Faraday's cage? Give its applications.

Consider a large plane wall of thickness L and thermal conductivity k in space. The wall is covered with white porcelain tiles that have an emissivity of and a solar absorptivity a. The inner surface of the wall is maintained at T1 at all times, while the outer surface is exposed to solar radiation that is incident at a rate of q. The outer

Find the mass of a flywheel having a radius of gyration of 1.13m which loses 16 kJ of energy when the speed falls. 10% below 180 rpm. Also calculate the torque necessary to increase the speed from rest to 180 rpm in 180 seconds.

L No friction,In the system of Figure 552, x(r) is the input displacement and 0(t) is the output angular displacement. Assume that the masses involved are negligibly small and that all motions are restricted to be small therefore, the system can be considered linear. The initial conditions for x and 8 are zeros, or x(0) 0 and 8(0) 0. Show that

(c) Your utility charges 0.08 for electricity. A PV module costs 2W installed. Should you switch to a combined PV grid system Explain your answer. 2W corresponds to 0.06kWhr (at 4 hrday over 20 years). It is cheaper to use solar if there is a way to store excess not being used. If the grid provides storage for free, then a hybrid system makes

A manometer shows a vacuum of 260 mm Hg. What will be the value of this pressure in N m in the form of absolute pressure and what will be absolute pressure (Nm), if the gauge pressure is 260 mm of Hg. Explain the difference between these two pressures.

An aerostat balloon is filled with hydrogen. It has a volume of 1000m at constant air temperature of 27C and pressure of 0.98bar. Determine the load that can be lifted with the air of aerostat.

A Utube manometer using mercury shows that the gas pressure inside a tank is 30cm. Calculate the gauge pressure of the gas inside the vessel. Take g 9.78ms, density of mercury 13,550kgm. (C.O.Dec03)

QUESTION: - Steam at a gauge pressure of 1.5MPa is supplied to a steam turbine, which rejects it to a condenser at a vacuum of 710mm Hg after expansion. Find the inlet and exhaust steam pressure in Pascal, assuming barometer pressure as 76cm of Hg and density of Hg as13.610 3 kg/m 3 .

1. A 3.6 m long shaft carries three pulleys, two at its two ends and third at the midpoint. The two end pulleys has mass of 85 kg and 20 kg and their centre of gravity are 3 mm and 5 mm respectively from the axis of the shaft. The middle pulley mass is 50 kg and its centre of gravity is 8 mm from the shaft axis. The pulleys are so keyed to the

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Uniform slender rod OA has weight Wrod 250 N and is held in equilibrium by cable AD, cable AC, and 1050 N is hung from the end of rod OA at point A. The ballandsocket joint O. A crate with weight Werate coordinates of points A, C, and D are A(4,1.5, 0.5) m . C (0, 4.5, 3) m D (0, 6.5, 0.5) m Determine the tension in cables AC and AD. TAC TAD N

Required information Air flows in a pipe under fully developed conditions with an average velocity of 1.25 ms and a temperature of 24C. The pipes inner diameter is 4 cm, and its length is 4 m. The first half of the pipe is kept at a constant wall temperature of 100C. The second half of the pipe is subjected to a constant heat flux of 200 W. The

The thin rectangular block is supported at its corners by small rollers resting on smooth horizontal surfaces. If b0.5 m and h 0.3 m, calculate the magnitude of the angular acceleration of the block at the moment when the supporting surface at B is suddenly removed. Present your answer in radsec using 3 significant figures. Ac B

In the realm of mechanical engineering, how do advances in material science, especially in the development of superalloys and composite materials, impact the design and efficiency of high-performance machinery, particularly in aerospace and automotive applications?

Dynamic viscosity of mixtures is expressed in terms of some of its constituents properties and flow conditions. A liquid filled with air bubbles is sheared in a flow cell between two parallel walls as shown in Figure 3. It is known that the dynamic viscosity of this mixture m is a function of the dynamic viscosity of water pw, water density pw,

(b)A spring mass system has spring stiffness s Nm and has a mass of m kg. It has the natural frequency of vibration as 12Hz.An extra 2kg mass is coupled to m and natural frequency reduces by 2Hz.Find the value of s and m

Question 2 Water flows through a tube with mean velocity of 0.2 ms. The mean inlet and outlet temperatures are 20C and 80C. The inside diameter of the tube is 0.5 cm. The surface is heated with a uniform heat flux of 0.6 Wcm. Determine the maximum surface temperature of the tube. Use the following properties Pr 3.57, p 988 kgm, Cp 4182 JkgC,

6. A typical heat pump may heat a home at a rate of 40,000 Btuhr. If a heat pump has a coefficient of performance of 3.6, how much power does it need to run, in hp According to Delmarva Power, the average cost of electricity is 14 cents per kilowatt hour. How much would it cost to run the heat pump all winter (say, 2000 hours) Round to the nearest

2. A cylindrical casting has a length of 0.5 m and a diameter of 600 mm. Another cuboidshaped casting (with the same metal material) is rectangular in crosssection, with a widthtothickness ratio of 2. The cuboidshaped casting has the same length and crosssectional area as the cylindrical casting. Both pieces are cast under the same conditions. The

Problem 2 For the beam and loading shown, determine the maximum normal stress due to bending on a transverse section at C. 10 kN I 1.5 m 1.5 m 3 kNm 2.2m 100 mm 200 mm

A shaft is rotating at a uniform angular speed. Four masses M1, M2, and M3 and M4 of magnitudes 300kg, 450kg, 360kg, 390kg respectively are attached rigidly to the shaft. The masses are rotating in the same plane. The corresponding radii of rotation are 200mm, 150mm, 250mmand 300mm respectively. The angle made by these masses with horizontal are

A vertical circular jet of liquid strikes a conical deflector having a mass m. The deflector is centered at the jet centerline and is supported by the fluid flow only. The entering jet has a diameter D. The magnitude of liquid velocity at the upper edge of the deflector equals to the entering velocity U. The liquid has a constant density, and the

A steel rod with one end hinge and one end fixed and having length of bmeter column and its section is is used rectangular (15mmx 10mm). Determine crippling by load as well as Crippling Stress Eulers Formula Take E as 200 G Pa (0)

If the tension developed in each of the cables cannot exceed 300 lb, determine the largest weight of the crate that can be supported. Also, what is the force developed along strut AD 5.5 ft 2 ft 2 ft 6 ft 4 ft 2.5 ft

Find and plot the shear (V) and bending moment (M) equations as functions of x. 14 kip 2 ft 2 ft 4 D 2 ft 4 kip DE MA B Somm

A steam pipe(K45Wmk) ID 75mm and OD 90mm is lagged with two successive layers of insulation. The layer in contact with the pipe is 38mm thick asbestos(K0.14Wmk) which is also covered with 25mm thick magnesia (K0.07Wmk). The film coefficients for inside and outside surfaces are 227 Wmk and 6.8 Wmk respectively. If the steam flowing through the tube

Q3. A steel pipe (K 45.0 Wm.K) having a 0.05m O.D is covered with a 0.042 m thick layer of magnesia (K 0.07Wm.K) which in turn covered with a 0.024 m layer of fiberglass insulation (K 0.048 Wm.K). The pipe wall outside temperature is 370 K and the outer surface temperature of the fiberglass is 305K. What is the interfacial temperature between