Which of the following relation is not true?
1
\(\mathrm{h}_{\mathrm{ib}}=\frac{\mathrm{h}_{\mathrm{ie}}}{1+\mathrm{h}_{\mathrm{fe}}}\)
2
\(\mathrm{h}_{\mathrm{fb}}=\frac{-\mathrm{h}_{\mathrm{fe}}}{1+\mathrm{h}_{\mathrm{fe}}}\)
3
\(\rm h_{r b}=\frac{h_{\mathrm{ie}} h_{\mathrm{re}}}{1+\mathrm{h}_{\mathrm{fe}}}\)
4
\(\rm h_{o b}=\frac{h_{o e}}{1+h_{f e}}\)