In case of single plate new clutches and brakes, the friction radius is equal to _________, where D and d are outer and inner diameters of friction lining respectively.
1
\(\frac{1}{3}\left(\frac{D^3~-~d^3}{D^2~-~d^2}\right)\)
2
\(\frac{1}{2}\left(\frac{D^3~-~d^3}{D^2~-~d^2}\right)\)
3
\(\frac{1}{4}\left(\frac{D^3~-~d^3}{D^2~-~d^2}\right)\)
4
\(\frac{1}{4}(D~+~d)\)
5
Question Not Attempted