# Elasticity

## For two different material it is given that Y1 > Y2 and B1 < B2. Here, Y is Young’s modulus of elasticity and B is the bulk modulus of elasticity. Then, we can conclude that

Q: For two different material it is given that Y1 > Y2 and B1 < B2 . Here, Y is Young’s modulus of elasticity and B is the bulk modulus of elasticity. Then, we can conclude that

(a) 1 is more ductile

(b) 2 is more ductile

(c) 1 is more malleable

(d) 2 is more malleable

Ans: (b) , (c)

## An aluminium rod having Young’s modulus 7 × 109 Nm-2 has a breaking strain of 0.2 % The minimum cross-sectional area of the rod (in m2) in order to support a load of 104 N is

Q: An aluminium rod having Young’s modulus 7 × 109 Nm-2 has a breaking strain of 0.2 % The minimum cross-sectional area of the rod (in m2) in order to support a load of 104 N is

(a) 1 × 10-2

(b) 1 × 10-8

(c) 1.4 × 10-2

(d) 7.1 × 10-4

Ans: (d)

## A thick uniform rubber of density 1.5 g cm^-3 and Young’s modulus 5 × 10^6 Nm-2 has a length of 8 m. When hung from the ceiling of a room. The increase in length of the rope due to its own weight will be

Q: A thick uniform rubber of density 1.5 g cm-3 and Young’s modulus 5 × 106 Nm-2 has a length of 8 m. When hung from the ceiling of a room. The increase in length of the rope due to its own weight will be (Given, g = 10 ms-2)

(a) 9.6 × 10-8 m

(b) 19.2 × 10-3 m

(c) 9.6 × 10-3 m

(d) 9.6 m

Ans: (a)

## When the pressure on all sides of a metal cube is increased by 10^7 Pa. its volume decreases by 0.015%. the bulk modulus of the metal is

Q: When the pressure on all sides of a metal cube is increased by 107 Pa. its volume decreases by 0.015%. the bulk modulus of the metal is

(a) 6.67 × 1010 pa

(b) 7.67 × 1010 Pa

(c) 5.67 × 1010 Pa

(d) 4.67 × 1010 Pa

Ans: (a)

## When the tension on wire is 4 units, its length is l1 and when the tension is 5 units, its length is l2 . Its natural length is

Q: When the tension on wire is 4 units, its length is l1 and when the tension is 5 units, its length is l2 . Its natural length is

(a) 4l1 – 3l2

(b) 5 l1 – 4l2

(c) 5l2 – 4 l1

(d) (l1 + l2)/2