A metal rod of length 40cm at 20°C is heated to a temperature of 45°C. If the new length of the rod is 40.05cm. Calculate its linear expansitivity
A
1.2 x \(10^{-5}K{-1}\)
B
2.5x \(10^{-5}K{-1}\)
C
3.5x \(10^{-5}K{-1}\)
D
4.5x \(10^{-5}K{-1}\)
E
5x \(10^{-5}K{-1}\)
Verified Correct Answer: E.
Physical Principles & Numerical Solution
\(\alpha = \frac{I_2-I_1}{I_1(\theta_2-\theta_1)} \\ \Rightarrow \frac{40.05 - 40}{40 \times (45-20)} = 5.0 \times10^{-5}\)
Source: Myschool Past Questions Archive (Record #26279)