Practice question

Given: A steel rod of length 1.5 m at 15° C is heated until its length becomes 1.5018 m . What is the temperature increase? ( α_l = 1.2 × 10⁻⁵ K^{-1 ) These values define the system as per NCERT data. Formula: Given: L_0 = 1.5 m, L = 1.5018 m, α_l = 1.2 × 10⁻⁵ K^{-1. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Δ L = 1.5018 - 1.5 = 0.0018 m . Δ L = L_0 α_l Δ T Rightarrow 0.0018 = 1.5 × 1.2 × 10⁻⁵ × Δ T . Δ T = frac0.00181.5 × 1.2 × 10⁻⁵= 100 K . 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.