Question

The length of a metallic rod is $5\, m$ at $0^{\circ} C$ and becomes $5.01\, m$, on heating upto $100^{\circ} C$. The linear expansion of the metal will be

• A. $2.33 \times 10^{-5} /{ }^{\circ} C$
• B. $6.0 \times 10^{-5} /{ }^{\circ} C$
• C. $4.0 \times 10^{-5} /{ }^{\circ} C$
• D. $2.0 \times 10^{-5} /{ }^{\circ} C$

Answer 1

Answer: (D)

$\ell=5 m $
$ t _1=0^{\circ} C$
$\ell_2=5.01 m $
$t _2=100^{\circ} C$
$\alpha=\frac{\ell_2-\ell_1}{\ell_1\left( t _2- t _1\right)}=\frac{5.01-5}{5 \times 100}$
$=2 \times 10^{-5} /{ }^{\circ} C$