A silver sheet has an area of 1.5m2 at 20∘C. What is the increase in area when heated to 120∘C? (αl\=1.9×10−5K−1)
Given: A0 = 1.5m2, ΔT = 120−20 = 100∘C, αl = 1.9×10−5K−1. ΔA = A0×2αlΔT = 1.5×2×1.9×10−5×100 = 0.0057m2. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 0.0057 m². This satisfies dimensional consistency and physical conditions given, so option D is scientifically correct.
Ref: NCERT Class 11 Physics, Chapter 11: Thermal Properties – Calorimetry.