The frictional torque transmitted in a truncated conical pivot bearing, considering uniform pressure, is
A
$$\frac{1}{2}\mu {\text{Wcosec}}\alpha \left( {{{\text{r}}_{\text{1}}} + {{\text{r}}_{\text{2}}}} \right)$$
B
$$\frac{2}{3}\mu {\text{Wcosec}}\alpha \left( {{{\text{r}}_{\text{1}}} + {{\text{r}}_{\text{2}}}} \right)$$
C
$$\frac{1}{2}\mu {\text{Wcosec}}\alpha \left( {\frac{{{\text{r}}_1^3 - {\text{r}}_2^3}}{{{\text{r}}_1^2 - {\text{r}}_2^2}}} \right)$$
D
$$\frac{2}{3}\mu {\text{Wcosec}}\alpha \left( {\frac{{{\text{r}}_1^3 - {\text{r}}_2^3}}{{{\text{r}}_1^2 - {\text{r}}_2^2}}} \right)$$
Correct Answer: $$\frac{2}{3}\mu {\text{Wcosec}}\alpha \left( {\frac{{{\text{r}}_1^3 - {\text{r}}_2^3}}{{{\text{r}}_1^2 - {\text{r}}_2^2}}} \right)$$
