NCERT Exercise 10.10 - Thermal Properties of Matter
Question: A brass rod (50 cm, 3 mm diameter) joined to a steel rod (same dimensions). Both at 40 C raised to 250 C. Find total change in length. Ends free. alpha_brass = 2.0 x 10^-5, alpha_steel = 1.2 x 10^-5 K^-1.
Answer: Total change = **3.36 x 10^-3 m = 3.36 mm**; **no thermal stress** (free ends).
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