In the circuit diagram, XY is a uniform resistance wire of length $L$. $R_1$ and $R_2$ are unknown resistors. J is a sliding contact that connects the junction of $R_1$ and $R_2$ to points on XY via a small signal lamp S. To find the ratio $\dfrac{V_1}{V_2}$ of the potential differences across $R_1$ and $R_2$, a point on XY is located where the lamp does not light. This point is a distance $x$ from X. What is the value of the ratio $\dfrac{V_1}{V_2}$?
- A$\dfrac{L}{x}$
- B$\dfrac{x}{L}$
- C$\dfrac{L-x}{x}$
- D$\dfrac{x}{L-x}$