In materials like aluminium and copper, the correct order of magnitude of various elastic moduli is: (a) Young's moduli < shear moduli < bulk moduli. (b) Bulk moduli < shear moduli < Young's moduli. (c) Shear moduli < Young's moduli < bulk moduli. (d) Bulk moduli < Young's moduli < shear moduli

Answer: (c). Typical values (in 10⁹ N m⁻²): Al: η ≈ 25, Y ≈ 70, B ≈ 72; Cu: η ≈ 42, Y ≈ 120, B ≈ 140. Also from Y = 2η(1+σ) with σ ≈ 0.33: η < Y, and Y = 3B(1-2σ) gives Y ≈ B, slightly less. Order: shear < Young's < bulk. So the answer is (c).

In materials like aluminium and copper, the correct order of… | JEE Main 2014 (9 Apr, Shift 1)

Q10JEE Main 2014 · 9 APR · SHIFT 1Easy

Shear Modulus & Poisson's Ratio

In materials like aluminium and copper, the correct order of magnitude of various elastic moduli is:

Show answer and solution

Answer: (c)

Typical values (in $10^{9}\ \text{N m}^{-2}$ ): Al: $\eta \approx 25$ , $Y \approx 70$ , $B \approx 72$ ; Cu: $\eta \approx 42$ , $Y \approx 120$ , $B \approx 140$ .
Also from $Y = 2\eta(1+\sigma)$ with $\sigma \approx 0.33$ : $\eta < Y$ , and $Y = 3B(1-2\sigma)$ gives $Y \approx B$ , slightly less.
Order: shear < Young's < bulk.
So the answer is (c).

Report a mistake

Shear Modulus & Poisson's Ratio question from JEE Main 2014 (9 Apr, Shift 1)

More questions on Shear Modulus & Poisson's Ratio