Question

If the Young's modulus of the material is 3 times its modulus of rigidity, then its volume elasticity will be

• A. Zero
• B. Infinity
• C. $2 \times 10 ^ { 10 } \mathrm {~N} / \mathrm { m } ^ { 2 }$
• D. $3 \times 10 ^ { 10 } \mathrm {~N} / \mathrm { m } ^ { 2 }$

Answer 1

Answer: (B)

Infinity

Answer 2

$Y = 2 \eta ( 1 + \sigma )$ ⇒ $3 \eta = 2 \eta ( 1 + \sigma )$⇒$\sigma = \frac { 3 } { 2 } - 1 = \frac { 1 } { 2 }$

Now substituting the value of σ in the following expression.

$Y = 3 K ( 1 - 2 \sigma )$ ⇒ $K = \frac { Y } { 3 ( 1 - 2 \sigma ) } = \infty$