The radius of a friction circle for a shaft rotating inside a bearing is (where r = Radius of shaft and $$\tan \varphi $$ = Coefficient of friction between the shaft and bearing)
A
$${\text{r}}\sin \varphi $$
B
$${\text{r}}\cos \varphi $$
C
$${\text{r}}\tan \varphi $$
D
$$\frac{{\text{r}}}{2}\cos \varphi $$
Correct Answer: $${\text{r}}\sin \varphi $$
