JNTU B.Tech II MECHANICS OF SOLIDS AND MECHANICS OF FLUIDS Previous Question Paper (April/May - 2023 - R16)

Define modulus of elasticity and modulus of rigidity.

What is a bulk modulus? How is the bulk modulus related to Young’s modulus?

What is meant by shear force and bending moment? Represent them with an example.

What do you mean by section modulus? Find an expression for section modulus of a circular cross section.

Define torsional rigidity of a shaft.

Specify the assumptions made in the derivation of shear stress produced in a circular shaft subjected to torsion.

Explain how liquid surface behaves when it is in contact with other surfaces.

Distinguish between gauge pressure, absolute pressure and vacuum pressure.

Define laminar and turbulent flow with one example for each.

State and prove Bernoulli’s equation.

A tensile load of 40 kN is acting on a rod of diameter 40 mm and of length 4 m. A bore of diameter 20 mm is made centrally on the rod along the length. To what length the rod should be bored so that the total extension will increase 30% under the same tensile load. Take Young’s modulus as 200 GPa.

A rod is 2 m long at a temperature of 100C. Find the expansion of the rod, when the temperature is raised to 800C. If this expansion is prevented, find the stress induced in the material of the rod. Take Young’s modulus as 200 GPa and α = 0.000012 per degree centigrade.

A bar 30 mm in diameter was subjected to tensile load of 50 kN and the measured extension on 300 mm gauge length was 0.12 mm and change in diameter was 0.004 mm. Calculate Poisson’s ratio and values of Young’s modulus, bulk modulus and modulus of rigidity.

Derive an expression for strain energy stored in a body due to shear stress alone.

A cantilever beam of length 3 m carries a uniformly distributed load of 2 kN/m run over a length of 2 m from the free end. It also carries a point load of 5 kN at a distance of 1m from the free end. Draw the shear force and bending moment diagrams.

The shear force changes suddenly at a section where there is a vertical point load. Justify the statement with a suitable diagram along with its shear force diagram.

A rectangular beam 200 mm deep and 300 mm wide is simply supported over a span of 8 m. What uniformly distributed load per metre the beam may carry, if the bending stress is not to exceed 120 MPa.

State the assumptions made in deriving bending equation. Also discuss the range of applicability of the equation.

Determine the power required to run a 300 mm diameter shaft at 400 rpm in journals with uniform oil thickness of 1 mm. Two bearings of 300 mm width are used to support the shaft. The dynamic viscosity of oil is 0.03 Pa-s.

A single column vertical manometer is connected to a pipe containing oil of specific gravity 0.9. The area of the reservoir is 80 times the area of the manometer tube. The reservoir contains mercury of specific gravity 13.6. The level of mercury in the reservoir is at a height of 300 mm below the centre of the pipe and difference of mercury levels in the reservoir and right limb is 500 mm. Find the pressure in the pipe.

Derive the relation between the centre of gravity and centre of pressure for an inclined surface immersed in a liquid.

A rectangular pontoon is 8 m long and 4 m wide. The weight of the pontoon is 400 kN. Find the position of centre of gravity above the base of the pontoon such that it does not overturn in still water.

A fluid flow is described by the velocity vector

Derive the equation of continuity for one-dimensional steady flow based on stream tube concept.

Find the relationship between a and b if in steady flow u = bx and v = ay.

The diameter and pressure at the inlet of the draft tube is 1 m and 0.45 bar (absolute), respectively. If the discharge of water is 1500 litres per second, pressure at the exit is atmospheric, and the vertical distance between the inlet and outlet is 5.6 m, then determine the exit diameter of the draft tube.

Explain briefly the various heads and forces acting on a flowing fluid.