JNTU B.Tech II PROPERTIES AND STRENGTH OF MATERIALS Previous Question Paper (November/December - 2017 - R13)

When is it required to quarry stones by blasting?

Classify different types of varnish and briefly describe them.

Name the ores required for making steel.

What are the diseases in timber?

Define thermal stresses and thermal strains.

What is Mohr’s circle? What is the importance of this circle?

What do you mean by slenderness ratio?

Write down the limitations of Euler’s formula for critical load.

What do you mean by ‘strength of a riveted joint’?

Define a fillet-weld joint and a butt joint.

State the effects of impurities present in the lime.

Describe briefly how lime is manufactured. Distinguish between quick, fat and hydraulic limes.

Describe the tests performed to check the quality of bricks.

Describe the process of manufacturing clay tiles.

What are the properties and uses of aluminium and nickel?

State the difference between mild steel and wrought iron.

What is seasoning of timber and why is it done?

Describe the physical and mechanical properties of timber.

Calculate the modulus of rigidity and bulk modulus of a cylindrical bar of diameter 30mm and length 1.5m if the longitudinal strain in a bar during a tensile stress is four times the lateral strain. Find the change in volume, when the bar is subjected to a hydrostatic pressure of 100N/mm². Take E= 1×10⁵ N/mm².

A beam 3m long, simply supported at its ends, is carrying a point load W at the centre. If the slope at the ends of the beam should not exceed 1°, find the deflection at the centre of the beam.

At a certain point in a strained material, the intensities of stresses on two planes at right angles to each other are 20N/mm² and 10N/mm² both tensile. They are accompanied by a shear stress of magnitude 10N/mm². Find the location of principal planes and evaluate the principal stresses and also draw the Mohr’s circle of stresses.

Derive an expression between modulus of elasticity and modulus of rigidity.

A solid round bar 4m long and 5cm in diameter was found to extend 4.6mm under a tensile load of 50kN. This bar is used as a strut with both ends hinged. Determine the buckling load for the bar and also find the safe load. Take factor of safety as 4.0.

A round steel rod of diameter 15mm and length 2m is subjected to a gradually increasing axial compressive load. Using Euler’s formula find the buckling load. Find also the maximum lateral deflection corresponding to the buckling condition, both ends of the rod may be taken as hinged. Take E= 2.1×10⁵ N/mm² and the yield stress of steel= 250N/mm².

A hollow circular column 2m long has one of its ends fixed and the other end free and has to support an axial load of 500kN. The internal diameter is 0.8 times the external diameter. Allowing a factor of safety of 4.0, calculate the external diameter and the thickness of metal. Use Rankine’s formula. Take crushing stress (fc) = 330N/mm² and α = 1/7500.

What are the assumptions made in Euler’s theory?

A single riveted double cover butt joint in a structure is used for connecting two plates 12mm thick. The diameter of rivets is 20mm. the permissible stresses are 150N/mm² in tension, 100 N/mm² in shear and 300 N/mm² in bearing. Calculate the necessary pitch and the efficiency of the joint.

Two steel plates 12cm wide and 1.30cm thick are to be joined by double lap weld joint. Find the length of the weld if the maximum tensile stress is not to exceed 72 N/mm² and maximum tensile load carried by the plate is 110kN.