Practice question

Given: A steel wire of length 2 m and cross-sectional area 2 × 10 ⁻⁶ m ² is stretched by a force of 200 N. If the Young's modulus of steel is 2 × 10 ¹¹ N/m ², what is the elongation of the wire? Formula: Using Young's modulus formula: Y = (F L) / (A ΔL). Substitution & Calculation: Rearrange for elongation: ΔL = (F L) / (A Y). Substitute values: ΔL = (200 × 2) / (2 × 10 ⁻⁶ × 2 × 10 ¹¹ ). Calculate: ΔL = 400 / (4 × 10 ⁵ ) = 10 ⁻³ m = 1 mm. Final Result: The computed value matches expected outcome and confirms correct choice as per latest NCERT 2026-27.