Question

The force required to stretch a wire of cross section 1 cm² to double its length will be ______.

(Given Young's modulus of the wire = 2 × 10¹¹ N/m²)

Options

• 1 × 10⁷ N

• 1.5 × 10⁷ N

• 2 × 10⁷ N

• 2.5 × 10⁷ N

Answer 1

The force required to stretch a wire of cross section 1 cm² to double its length will be 2 × 10⁷ N.

Explanation:

Force F = `YA (Deltai)/l` 

Y = Young's modulus of the wire

= `2 xx 10^11 xx 10^-4((2l - l)/l) = 2 xx 10^7` N