Strenght of Materials

36

When a rectangular bar of length l, breadth b and thickness t is subjected to an axial pull of P, then linear strain (`epsilon`) is given by (where E = Modulus of elasticity)

A. `epsilon = (p)/(b.t.E)`
B. `epsilon = (b.t.E)/(p)`
C. `epsilon = (b.t)/(p.E)`
D. `epsilon = (p.E)/(bt)`

37

A simply supported beam of length l is loaded with a uniformly distributed load of w per unit length. The maximum deflection is`(5Wl^5)/(384EI)` and lies at the centre of the beam.

A. True
B. . False

38
A thin cylindrical shell of diameter (d), length (l) and thickness (t) is subjected to an internal pressure (p). The ratio of longitudinal strain to hoop strain is
A. `(m - 2)/(2m - 1)`
B. `(2m - 1)/(m - 2)`
C. `(m - 2)/(2m +1)`
D. `(2m +1)/(m - 2)`

39

The horizontal thrust offered by the retaining wall on the retained material is (where w = Specific weight of the retained material, h = height of retaining wall, and (`phi`) = Angle of repose of the retained earth)

A. `(Wh^2)/(2) ((1 + sin phi)/(1 - sin phi))`
B. `(Wh^2)/(2) ((1 - sin phi)/(1+ sin phi))`
C. `(Wh^2)/(2) ((1 + cos phi)/(1 - cosphi))`
D. `(Wh^2)/(2) ((1 - cos phi)/(1 +cos phi))`

40

The tensile strength of the welded joint for double fillet is (where s = Leg or size of the weld, l = Length of weld, and `sigma_t`= Allowable tensile stress for weld metal)

A. `0.5 s.l.sigma_t`
B. ` s.l.sigma_t`
C. `sqrt(2) s.l.sigma_t`
D. `2 s.l.sigma_t`