Correct option: (B) \(0.004\)
Explanation:
Given : \(L=2 m\)
\(r=1 \mathrm{~cm}=10^{-2} \mathrm{~m}\)
twist \(=\theta=0.8 \mathrm{rad}\)
angle of shear \(=\phi\)
\(=(\mathrm{r} \theta / \mathrm{L})\)
\(=\left\{\left(10^{-2} \times 0.8\right) / 2\right\}\)
\(=0.4 \times 10^{-2}\)
i.e. shear strain \(=0.004 \mathrm{rad}\)