Mechanical Engineering Sample Exam Questions (Part-1)

Topics-Hydraulics & Hydraulic Machinery

Scope of hydraulics:
⬥ Define fluid with types.
⬥ Compare the liquid, vapor and gas.
⬥ Define hydraulics and hydraulic machineries.
⬥ Outline the importance of hydraulics and hydraulic machineries.
⬥ Mention the branches of hydraulics.
⬥ Identify different application of hydraulics and hydraulic machineries in engineering field.

➥ Fluid properties and fluid pressure:
⬥ List the properties of fluids.
⬥ Define density, specific weight, surface tension, capillary, viscosity and fluid pressure.
⬥ State Pascal’s law of fluid pressure.
⬥ Show the proof of the Pascal’s law of fluid pressure.
⬥ Define atmospheric pressure, gauge pressure and absolute pressure.
⬥ Mention the relation among atmospheric pressure, gauge pressure and absolute pressure.
⬥ Express the derivation of the formulae for finding total pressure on immerged surface at horizontal, inclined and vertical position.

➥ Buoyancy:
⬥ Define buoyancy and center of buoyancy.
⬥ State the meaning meta-centre and meta-centric height.
⬥ Mention the conditions of equilibrium of a floating body.

➥ Features of fluid pressure gauges:
⬥ State the meaning of pressure gauge.
⬥ Mention the classification of pressure gauges.
⬥ Define manometer.
⬥ Distinguish between simple manometer and differential manometer.
⬥ Mention the working principle of different types of pressure gauges.
⬥ Mention the specific application of different pressure gauges.

➥ Fluid flow through pipes:
⬥ State different types of fluid flow.
⬥ State the equation of continuity of flow.
⬥ State flow rate or discharge.
⬥ Compute the formula of flow rate.
⬥ State the equation of continuity of flow

➥ Concept of Bernoulli’s equation:
⬥ State and interpret the Bernoulli’s equation for flowing liquid.
⬥ Mention the limitation of Bernoulli’s equation.
⬥ Mention the function of venture-meter, orifice-meter and pitot tube.
⬥ Describe the construction and operation of venture-meter, orifice-meter and pitot tube.
⬥ Express the derivation of formula to measure the quantity of liquid flowing through venture-meter.
⬥ Express the derivation of formula to measure the quantity of liquid flowing through orifice-meter.
⬥ Express the derivation of formula to measure the velocity of flowing liquid by the pitot tube.

➥ Flow through orifices:
⬥ Define orifice.
⬥ Mention the classification of orifices.
⬥ State hydraulic coefficients.
⬥ Define jet of water, vena-contracta, coefficient of contraction (Cc), coefficient of velocity (Cv), coefficient of discharge (Cd) and coefficient of resistance.
⬥ Relate the Cc, Cv and Cd.
⬥ Calculate different hydraulic coefficients.
⬥ Express the deduction of formulae for finding out the discharge of liquid through various orifices

➥ Flow through mouthpieces:
⬥ Define and classify mouthpieces.
⬥ Express the deduction of formulae to calculate discharge through different types of mouthpieces.
⬥ State head losses of flowing liquid in a pipe.
⬥ List the causes of head loss of flowing liquid.
⬥ Express the deduction of formulae to calculate loss of head due to friction, sudden enlargement, sudden contraction and obstruction in pipe.
⬥ Express the deduction of formulae to calculate loss of head due to friction (Darcy’s and Cheay’s formulae)

➥ Flow through notches and Weirs:
⬥ Define notches and Weirs.
⬥ Identify different types of notches and Weirs with sketches such as rectangular notch v-notch trapezoidal notch.
⬥ Outline the importance of using notches and Weirs.

➥ Concept of viscous flow:
⬥ Define viscosity.
⬥ Mention the units of viscosity.
⬥ Define ideal fluid, real fluid, Newtonian fluid and non-Newtonian fluids.
⬥ Distinguish between the laminar flow and turbulent flow.
⬥ State Reynold’s number

➥ Aspect of impact of jets:
⬥ State impact of jet.
⬥ Express the deduction of formula to calculate the force of a jet impinging on a flat fixed vertical plate, inclined plate and hinged plate

➥ Features of water turbines:
⬥ State the meaning of water turbine.
⬥ Mention the classification of water turbine.
⬥ Describe the principle of impulse and reaction water turbine.
⬥ Compare the impulse and reaction turbine.
⬥ Describe the construction of Pelton, Kaplan and Francis water turbine.
⬥ Describe the operation of Pelton, Kaplan and Francis water turbine.
⬥ State the specific speed of turbine.
⬥ Describe the governing system of impulse and reaction turbines.
⬥ Define draft tube and its classification.

➥ Features of reciprocating pumps:
⬥ Define reciprocating pump.
⬥ Mention the classification of reciprocating pumps.
⬥ Describe the construction of various reciprocating pumps.
⬥ Describe the operation of different types of reciprocating pumps.
⬥ State the meaning of slip of reciprocating pumps.
⬥ Mention the function of air vessel in single acting reciprocating pump.
⬥ Describe the operation of suction side and discharge side air vessel in a single acting reciprocating pump.
⬥ Express the deduction of formula to calculate the discharge of reciprocating pumps.

➥ Features of centrifugal pumps:
⬥ State the meaning of centrifugal pump.
⬥ Mention the classification of centrifugal pumps.
⬥ Compare the centrifugal and reciprocating pumps.
⬥ Describe the construction of various centrifugal pumps.
⬥ Describe the operation of different types of centrifugal pumps.
⬥ State the meaning of cavitation of centrifugal pumps.
⬥ Express the deduction of formula to calculate discharge of centrifugal pumps.
⬥ Power required to drive a centrifugal pump.
⬥ Mention the efficiencies of centrifugal pump.

➥ Features of rotary pumps:
⬥ State what is meant by rotary pump.
⬥ Mention the classification of rotary pumps.
⬥ Describe the construction of various rotary pumps.
⬥ Describe the operation of different types of rotary pumps.
⬥ List the advantages and disadvantage of rotary pumps over centrifugal and reciprocating pumps.
⬥ Mention the application of rotary pumps.

➥ Features of hydraulic devices:
⬥ State hydraulic devices.
⬥ Identify the hydraulic devices.
⬥ Mention the function of hydraulic devices viz. hydraulic press, hydraulic accumulator, hydraulic intensifier, hydraulic crane, hydraulic lift, etc.
⬥ Describe the construction of various hydraulic devices.
⬥ Describe the operation of different types of hydraulic devices.