What is the maximum torque transmitted by a hollow shaft of external radius ‘R’, internal radius ‘r’ and maximum allowable shear stress τ?
1
\(\frac{\pi}{16}(R^3-r^3)\tau\)
2
\(\frac{\pi}{2R}(R^4-r^4)\tau\)
3
\(\frac{\pi}{8R}(R^4-r^4)\tau\)
4
\(\frac{\pi}{32}(R^4-r^4)\tau\)