⚙️ Mechanical Eng Solved MCQs with Answers

Practice 934 approved ⚙️ Mechanical Eng questions with verified answers from the 🛠️ Engineering Essentials subject for Pakistan exams.

934 solved MCQs

When a pattern is made in three parts, the bottom part is known as a cope.Answer: False The discharge over a rectangular notch is (where b = Width of notch, and H = Height of liquid, above the sill of the notch)Answer: 2/3 Cᵈ x b√2g x H³ᐟ² In __________ welding, the weld may be made either from left to right or from right to left.Answer: vertical The discharge through a siphon spillway isAnswer: Cᵈ x a√2gH The maximum discharge over a broad crested weir isAnswer: 1.71 Cᵈ x L x H³ᐟ² In a venturimeter, the velocity of liquid at throat is __________ than at inlet.Answer: higher The loss of head due to friction in a pipe of uniform diameter in which a viscous flow is taking place, is (where RN = Reynold number)Answer: 16/Rₙ Which of the following is an example of laminar flow?Answer: all of these The pressure less than atmospheric pressure is known asAnswer: all of these The total energy line lies over the hydraulic gradient line by an amount equal to theAnswer: velocity head A structure whose width is __________ the width of the channel, is called a flumed structure.Answer: less than The maximum efficiency of transmission through a pipe isAnswer: 66.67% The coefficient of viscosity may be determined byAnswer: all of these The stability of a dam is checked forAnswer: all of these An ideal fluid is frictionless and incompressible.Answer: Correct A manometer is used to measureAnswer: high pressure The centre of gravity of the volume of the liquid displaced is calledAnswer: centre of buoyancy The coefficient of discharge for an external mouthpiece isAnswer: 0.855 A siphon is used to connect two reservoirs at different levels intervened by a high ridge.Answer: True A flow in which the volume of a fluid and its density does not change during the flow is called __________ flow.Answer: incompressible The loss of head due to an obstruction in a pipe is twice the loss of head at its entrance.Answer: Agree The body will sink down if the force of buoyancy is __________ the weight of the liquid displaced.Answer: less than If a body floating in a liquid returns back to its original position, when given a small angular displacement, the body is said to be inAnswer: stable equilibrium The pressure measured with the help of a piezometer tube is inAnswer: head of liquid The power transmitted through a pipe is (where w = Specific weight in N/m³, and Q = Discharge in m³/s)Answer: w x Q (H - hᶠ) In an external mouthpiece, the absolute pressure head at vena contracta is __________ the atmospheric pressure head by an amount equal to 0.89 times the height of the liquid, above the vena contracta.Answer: less than The weight per unit volume of a liquid at a standard temperature and pressure is calledAnswer: specific weight The centre of buoyancy is the centre of area of the immersed body.Answer: Correct The metacentric heights of two floating bodies A and B are 1 m and 1.5 m respectively. Select the correct statement.Answer: The body B is more stable than body A In open channels, the specific energy is theAnswer: total energy measured with respect to the datum passing through the bottom of the channel