If Young modulus (Y) equal to bulk modulus (B). Then the Poisson ratio is :

1. $\frac{1}{3}$

2. $\frac{2}{3}$

3. $\frac{1}{2}$

4. $\frac{1}{4}$

Bridges are declared unsafe after a long time of their use due to:

(1) Elastic after effect

(2) Elastic fatigue

(3) Plasticity

(4) Both (1) & (2)

A steel wire is fixed at its one end on the roof. At other ends of the wire, 1 kg mass is hanged so that the energy stored in the wire is E. The energy stored in the same wire if we hang 2 kg mass instead of 1 kg is:

(1) 2E

(2) 4E

(3) 8E

(4) E

The bulk modulus of a rubber ball is $9\times {10}^8 \mathrm{N}/{\mathrm{m}}^2$. To what depth below the surface of the sea, should the ball be taken so as to decrease its volume by 0.1%?

(1) 1 m

(2) 10 m

(3) 90 m

(4) 1 km

What is the value of Poisson's ratio for an incompressible material?

(1) Zero

(2) 0.2

(3) 0.5

(4) Infinite

If the Poisson's ratio of a material is 0.5, then its bulk modulus is equal to:

(1) Zero

(2) Young's modulus

(3) Infinite

(4) Three times Young's modulus

A uniform wire of cross-sectional area A is stretched by a certain force so that its length is elongated by x. What should be the cross-sectional area of the wire, so that elongation becomes $\frac{\mathrm{x}}{2}$ on applying the same force?

(1) A

(2) 2A

(3) 4A

(4) 8A

A wire suspended vertically from one of its ends is stretched by attaching a weight of 100 N. If the elastic energy stored in the wire is 0.1 J. The elongation in the wire is:

(1) 1 mm

(2) 2 mm

(3) 3 mm

(4) 4 mm