COMEDK · Physics · 12. Thermal Properties of Matter
A thin copper wire of length \(L\) increases in length by \(1 \%\), when heated from temperature \(T_1\) to \(T_2\). What is the percentage change in area when a thin copper plate having dimensions \((10 L \times 2 L)\) is heated from \(T_1\) to \(T_2\) ?
- A \(2 \%\)
- B \(20 \%\)
- C \(10 \%\)
- D \(40 \%\)
Answer & Solution
Correct Answer
(A) \(2 \%\)
Step-by-step Solution
Detailed explanation
\(\begin{aligned} & \text { } A=10 L \times 2 L=20 L^2 \\ & \frac{\Delta A}{A} \times 100=2 \frac{\Delta L}{L} \times 100=2 \times 1=2 \%\end{aligned}\)
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