The radius of \( 2^{\text{nd}} \) orbit of \( \text{He}^{+} \) of Bohr’s model is \( r_{1} \) and that of fourth orbit of \( \text{Be}^{3+} \) is represented as \( r_{2} \). Now the ratio \( \dfrac{r_{2}}{r_{1}} \) is \( x : 1 \). The value of \( x \) is ________.
