The ratio of the linear expansivity of copper to that of iron is approximately 1.5. A specimen of iron and a specimen of copper expands by the same amount per unit rise in temperature. The ratio of their length is

A.

3

B.

1.5

C.

1.32

D.

1

E.

0.67

Correct answer is E

\(\alpha_1\)L1 = \(\alpha_2\)L2

\(\frac{L_1}{L_2}\) = \(\frac{\alpha_1}{1.5\alpha_2}\) (since a1- 1.5\(\alpha_2\))


\(\frac{L_1}{L_2}\) = 0.67