Question

Two wires of equal length and cross-section area suspended as shown in figure. Their Young's modulus are Y 1 and Y 2 respectively. The equivalent Young's modulus will be

(A) Y 1 + Y 2 (B) Y1+Y22 (C) Y1Y2Y1+Y2 (D) ?Y1Y2

Answer 1

As there is no figure attached, it can't be answered properly but here I'm putting some generalised steps which may help u.

Young's modulus (Y) = (F/A) / (L/ΔL) = FL / AΔL

As the two wires have same length and cross section area,

Y₁ = F₁L / AΔL₁

or, L/A = Y₁ΔL₁ / F₁

and; Y₂ = F₂L / AΔL₂

or, L/A = Y₂ΔL₂ / F₂

Therefore,

Y₁ΔL₁ / F₁ = Y₂ΔL₂ / F₂

Now here, put the values of force acting on both the strings and the relation between Y₁ and Y₂ can be deducted.

Answer 2

Answer: (Y1 +Y2)/2

Explanation: