Practice question

Given: A copper sheet has an area of 2 m² at 25° C . What will be its area at 225° C ? ( α_l = 1.7 × 10⁻⁵ K^{-1 ) These values define the system as per NCERT data. Formula: Given: A_0 = 2 m², Δ T = 225 - 25 = 200° C, α_l = 1.7 × 10⁻⁵ K^{-1. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Area expansion: Δ A = A_0 × 2 α_l Δ T = 2 × 2 × 1.7 × 10⁻⁵ × 200 = 0.0136 m² . New area: A = A_0 + Δ A = 2 + 0.0136 = 2.0136 m² . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.