Engineering Q & a's

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    Section Number: 1

    1) What is the term used when the lubricant film is microscopically thin?Thermodynamics, Heat Transfer & MechanicsA: Film lubrication.B: Minimal lubrication.C: Boundary lubrication.D: Layer lubrication.2) In the sketch ENG154, which of the curves represents isothermal compression?Thermodynamics, Heat Transfer & MechanicsA: AB: BC: CD: D3) In the sketch ENG154, which of the curves represents polytropic compression?Thermodynamics, Heat Transfer & MechanicsA: AB: BC: CD: D4) The centrifugal force applied to a rotating body is given by the equation

    Thermodynamics, Heat Transfer & MechanicsA: mass multiplied by the velocity cubed divided by radius.B: mass multiplied by the radius divided by velocity squared.C: radius multiplied by the velocity squared divided by mass.D: mass multiplied by the velocity squared divided by radius.5) In an internal combustion engine, the thermal efficiency is given by the expressionThermodynamics, Heat Transfer & MechanicsA: heat supplied/heat losses.B: heat turned into work/heat supplied.C: heat supplied/heat turned into work.D: required to change from solid to gas.6) A pressure supports a 250mm column of water in a water manometer. What pressuredoes this represent

    in kN/square metre?Thermodynamics, Heat Transfer & MechanicsA: 244.3 N/square metre.B: 245.3 kN/square metre.C: 246.1 kN/square metre.D: 242.2 kN/square metre.Section Number: 1

    7) A 100mm shaft runs at 500rpm, the total load on the bearings is 25kN, coefficient offriction is 0.04.Calculate the work lost to friction every second.Thermodynamics, Heat Transfer & MechanicsA: 2,618JB: 1.57kJC: 26.18kJD: 4,526J8) The lengths of a vertical upright, jib and tie of a crane are 8, 13 and 9 metresrespectively find the force inthe jib when a load of 20kN is suspended from the crane.Thermodynamics, Heat Transfer & MechanicsA: 32.5kNB: 22.5kNC: 28.9kND: 14.6kN

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    9) 3.5 cubic metres of gas at 18C is heated at constant pressure to 200C. What is the finalvolume?Thermodynamics, Heat Transfer & MechanicsA: 5.75 cubic metres.B: 5.69 cubic metres.C: 4.95 cubic metres.D: 5.93 cubic metres.10) When a sliding body is being pulled up an incline by a horizontal force, the forceresisting motion isexpressed asThermodynamics, Heat Transfer & MechanicsA: weight of body multiplied by the sin(incline angle + reaction angle).B: weight of body multiplied by the cos(incline angle + reaction angle).C: weight of body multiplied by the tan(incline angle + reaction angle).D: vertical component of the weight.11) The product of head and force of gravity of a liquid is the liquid'sThermodynamics, Heat Transfer & MechanicsA: kinetic energy.B: potential energy.C: pressure energy.

    D: volume energy.12) A block of wood is pulled along a horizontal surface by a force of 25N @ 20 above thehorizontal. What isthe horizontal component of the force?Thermodynamics, Heat Transfer & MechanicsA: 9.88NB: 8.55NC: 23.49ND: 22.73NPAGE 2Section Number: 1

    13) The method of lettering space and vector diagrams is calledThermodynamics, Heat Transfer & Mechanics

    A: Bell's notation.B: Force notation.C: Consecutive letter notation.D: Bow's notation.14) On a cylindrical pressure vessel with dished ends, the stress on the circumferential iscalculated byThermodynamics, Heat Transfer & MechanicsA: multiplying pressure by the total area of the ends.B: multiplying pressure by half the total area of the ends.C: multiplying pressure by the projected area of the ends.D: multiplying pressure by half the projected area of the ends.15) A vertical downward force of 17N is applied to a body and a horizontal force of 20N.What is themagnitude and direction of the resultant of these two forces?Thermodynamics, Heat Transfer & MechanicsA: 32N @ 40 22' to the horizontal.B: 32N @ 50 38' to the horizontal.C: 26.25N @ 40 22' to the horizontal.D: 27.55N @ 40 22' to the horizontal.16) When a sliding body is being pulled up an inclined plane, the force required toovercome friction isThermodynamics, Heat Transfer & MechanicsA: more than on a level surface.

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    B: the same as on a level surface.C: small enough to be ignored.D: less than on a level surface.17) Find the volume of air at 1.5 bar required to compress to 2 cubic metres at 40 bar withno increase intemperature.Thermodynamics, Heat Transfer & MechanicsA: 40 cubic metres.B: 46.3 cubic metres.C: 53.33 cubic metres.D: 56.66 cubic metres.18) A body being rotated around a fixed point with circular motion at constant velocity isconsidered to besubject toThermodynamics, Heat Transfer & MechanicsA: centripetal velocity.B: centripetal acceleration.C: centrifugal acceleration.D: centrifugal velocity.PAGE 3

    Section Number: 119) 2.3 cubic metres of air at 1 bar is compressed to 0.57 cubic metres at constanttemperature. What is thefinal volume?Thermodynamics, Heat Transfer & MechanicsA: 4.12 cubic metres.B: 4.07 cubic metres.C: 4.14 cubic metres.D: 4.04 cubic metres.20) The expression P1xV1/T1=P2xV2/T2 is attributable toThermodynamics, Heat Transfer & MechanicsA: Boyle's Law.B: Charles' Law.

    C: Combined Gas Laws.D: Dalton's Law.21) If an evaporator is operated at less than 0.1 bar, at approximately what temperaturewould the water boil?Thermodynamics, Heat Transfer & MechanicsA: 100CB: 80CC: 60CD: 30C22) A bar 300mm long carries loads of 40, 30, 20 and 50N at distances of 70, 120, 200 and240mm respectivelyfrom the left end. Neglect the weight of the bar and find the position of a single balancingsupport.Thermodynamics, Heat Transfer & MechanicsA: 145mm from the left.B: 140mm from the left.C: 160mm from the left.D: 155mm from the left.23) With a simple pendulum, at what point is the body receiving maximum acceleration?Thermodynamics, Heat Transfer & MechanicsA: At mid travel.B: At the end of its travel.C: Approaching mid travel.

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    D: Leaving the end of its travel.24) With reference to harmonic motion, the "periodic time" is the time taken toThermodynamics, Heat Transfer & MechanicsA: move from the centre of travel to the end of travel.B: move from one end of travel to the other.C: move from one end of travel and return.D: move from the centre of travel and return.PAGE 4Section Number: 1

    25) What must be taken into account when calculating the liquid flow through an orifice?Thermodynamics, Heat Transfer & MechanicsA: Coefficient of volume.B: Coefficient of area.C: Coefficient of discharge.D: All of these must be taken into account.26) Which of the following can be performed using Archimede's Principle?Thermodynamics, Heat Transfer & MechanicsA: Determine the Centre of Gravity of a submerged body.B: Determine the volume of an irregular shaped body.C: Determine the centre of flotation of a semi submerged body.

    D: Determine the relative density of a semi submerged body.27) A diesel engine uses 800kg of fuel per hour of calorific value 42MJ/kg. If 35% of thisheat is convertedinto useful work, find the shaft power.Thermodynamics, Heat Transfer & MechanicsA: 3,345kWB: 3,267kWC: 2,760kWD: 2,913kW28) On a Michell main thrust bearing, how is the oil film allowed to form?Thermodynamics, Heat Transfer & MechanicsA: By allowing the pads to pivot.B: By the radial grooves in the thrust collar.

    C: By allowing adequate axial clearance.D: By tapering the contact surface of the pads.29) In a set of rope blocks with 3 pulleys in the top and 2 in the bottom, it takes 300N to lifta load of 1.26kN.Find the velocity ratio and mechanical advantage.Thermodynamics, Heat Transfer & MechanicsA: 6 & 4.1B: 5 & 4.4C: 6 & 4.6D: 5 & 4.230) A body with an initial velocity of 10m/sec is given uniform acceleration of 2m/sec/secfor 6 seconds. What isthe velocity after 6 seconds?Thermodynamics, Heat Transfer & MechanicsA: 16m/second.B: 22m/second.C: 52m/second.D: 18m/second.PAGE 5Section Number: 1 QuestionNumber

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    31) A steel tie bar,of tensile strength 462MN/square metre carries a tensile load of 11.12kN.Find its diameterallowing a factor of safety of 12.Thermodynamics, Heat Transfer & MechanicsA: 16.7mmB: 21.3mmC: 19.17mmD: 19.97mm32) A gas at 15C and 1 bar is heated at constant volume to 200C. What is the final gaspressure?Thermodynamics, Heat Transfer & MechanicsA: 1.64 bar.B: 1.51 bar.C: 1.57 bar.D: 1.62 bar.33) What percentage of oxygen is present in the atmosphere?Thermodynamics, Heat Transfer & MechanicsA: 20%B: 23%C: 25%

    D: 19%34) What factor is the most important in establishing an oil film in a bearing?Thermodynamics, Heat Transfer & MechanicsA: The loading of the bearing.B: The supply pressure of the lubricant.C: The rotational speed of the shaft.D: The bearing material.35) When applying gas laws, the gas pressure is taken asThermodynamics, Heat Transfer & MechanicsA: gauge pressure.B: gauge pressure plus atmospheric pressure.C: gauge pressure minus atmospheric pressure.D: the difference between gas and atmospheric pressures.

    36) On a crosshead type diesel engine, where would film lubrication be most difficult toestablish?Thermodynamics, Heat Transfer & MechanicsA: Bottom end bearing.B: Crosshead bearing.C: Crosshead guide shoes.D: Main journal bearing.PAGE 6NumberSection Number: 1

    37) When a sliding body is being pulled up an incline, the force required to overcomefriction is given byThermodynamics, Heat Transfer & MechanicsA: weight of body multiplied by the sin of incline angle.B: weight of body multiplied by the cos of incline angle.C: horizontal component of the weight..D: vertical component of the weight.38) The press