In an electric circuit, a cell of certain emf provides a potential difference of \( 1.25 \, \text{V} \) across a load resistance of \( 5 \, \Omega \). However, it provides a potential difference of \( 1 \, \text{V} \) across a load resistance of \( 2 \, \Omega \). The emf of the cell is given by \( \dfrac{x}{10} \, \text{V} \). Then the value of \( x \) is _______.