Mechanics of Materials_22ME42

The ability of a material to deform without breaking is called

• elasticity

• Plasticity

• Creep

• Fatigue

When mild steel is subjected to tensile load, its fracture will conform to

• star shape

• granular shape

• Cup and cone shape

• Fibrous shape

Which of the following expresses the total elongation of a bar of length L with a constant cross section area A and modulus of elasticity E hanging vertically and subjected to its own weight W

• WL/AE

• WL/2AE

• 2WL/AE

• WL/4AE

A steel bar 600mm long and having 30mm diameter, is turned down to 25mm diameter for one fourth of its length. It is heated at 30 C above room temperature, clamped at both ends and then allowed to cool to room temperature. If the distance between the clamps is unchanged, the maximum stress in the bar ( α = 12.5 x 10-6 per C and E = 200 GN/m2) is

• 25 MN/m2

• 40 MN/m2

• 50 MN/m2

• 75 MN/m2

If rod expands freely due to heating, it will develop

• Bending stress

• Thermal stress

• No stress

• shear stress

The radius of a Mohr circle will be zero when

• σx = σy

• σx ≠ σy

• σx ≥ σy

• σx ≤ σy

Shear stress on the principle plane is equal to

• zero

• maximum

• bending stress

• none

SFD will not get affected by

• Point Load

• UDL

• UVL

• Moment

When beam is subjected to various loads, BM will be max when SF is

• max

• min

• 0

• Infinity

What is the maximum shear force, when a cantilever beam is loaded with udl of W N/m throughout the span L?

• WL

• W

• W/L

• WL/2