Design of Machine Elements

A bracket is welded to the vertical column. The welded joint undergoes torsional stresses.

• True

• False

A bracket is shown welded to a vertical column by means of two fillet welds. The bending stress induced in the welds can be given by

• My/I

• 2My/I

• My/2I

• None of the listed

Find the bending stress in the top weld is_______, if thickness of weld is 't'. Given P=15kN and e=120mm, y=50mm and I = 250000 t

• 230/t

• 360/t

• 200/t

• None of the listed

Testing the ultimate strength of the weld falls in non-destructive examination.

• True

• False

Martin’s factor compensates for curvature effect in springs.

• True

• False

The angle of twist for the equivalent bar to a spring is given by?

• 8PD²N/Gd⁴

• 16PD²N/Gd⁴

• 16PDN/Gdᵌ

• 8PDN/Gdᵌ

A spring of stiffness constant k is cut in two equal parts. The stiffness constant of new spring will be k/2.

• True

• False

Find the Wahl’s factor if spring index is 6.

• 1.2020

• 1.2424

• 1.2525

• 1.5252

Find the shear stress in the spring wire used to design a helical compression spring if a load of 1200N is applied on the spring. Spring index is 6, and wire diameter 7mm.

• 452.2N/mm²

• 468.6 N/mm²

• 512.2 N/mm²

• None of the listed

Find total number coils in a spring having square and ground ends. Deflection in the spring is 6mm when load of 1100N is applied. Modulus of rigidity is 81370N/mm². Wire diameter and pitch circle diameter are 10mm and 50mm respectively.

• 7

• 6

• 5

• 4