Expression for effective radius factor k in terms of radius of curvature rc and radius of earth re?

\(k=\frac{1}{1-\frac{r_c}{r_e}} \)

\(k=\frac{1}{1-\frac{r_e}{r_c}} \)

Expression for effective radius factor k in terms of radius of curvat

1.	Expression for effective radius factor k in terms of radius of curvature rc and radius of earth re?
A.	\(k=\frac{1}{1-\frac{r_c}{r_e}} \)
B.	\(k=\frac{1}{1-\frac{r_e}{r_c}} \)
C.	\(k= 1-\frac{r_e}{r_c} \)
D.	\(k= 1-\frac{r_c}{r_e} \)
Answer» C. \(k= 1-\frac{r_e}{r_c} \)