A bimetallic strip is made of brass and iron as shown below. At room temperature, it is straight. The coefficients of linear expansion for brass and iron are: brass = 2.4 x 10^-5 K^-1, iron = 1.1 x 10

Question

A bimetallic strip is made of brass and iron as shown below. At room temperature, it is straight.

The coefficients of linear expansion for brass and iron are: brass = 2.4 x 10^-5 K^-1, iron = 1.1 x 10^-5 K^-1. Which of the following correctly states what will happen to the free end when the temperature of the strip is increased or decreased? (first entry: temperature increased, second entry: temperature decreased)

TestHub · Accepted Answer

Brass has the larger coefficient (2.4e-5 vs 1.1e-5 per K). On heating, the brass side expands more and becomes the outer (longer) side of the bend, so the strip curves toward the iron side - with brass on top, the free end bends down. On cooling, brass contracts more and the free end bends up. Answer A.

Physics - Heat & Thermo Question with Solution | TestHub

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