Question

If the modulus of elasticity is 130 GPa and Poisson’s ratio is 0.3 of steel then what will be the approximate value of modulus of rigidity of steel in MPa?
1. 110000
2. 50
3. 50000
4. 110

Answer 1

Correct Answer - Option 3 : 50000

Concept:

The relation between E, G, μ, and K will be

E = 2G(1 + μ),

E = 3K(1 – 2μ)

Where E = Young’s Modulus, G = Modulus of Rigidity, μ = Poisson ratio, K = Bulk modulus of Elasticity.

Calculation:

Given:

E = 130 GPa = 130 × 10³ MPa, μ = 0.3

E = 2G (1 + μ)

130 × 103 = 2G (1 + 0.3)

G = 50000 MPa

∴ the modulus of rigidity of steel in 50000 MPa.