X P Q Y is a vertical smooth long loop having a total resistance R where P X is parallel to Q Y and separation between them is l. A constant magnetic…

$\displaystyle X P Q Y$ is a vertical smooth long loop having a total resistance $\displaystyle R$ where $\displaystyle P X$ is parallel to $\displaystyle Q Y$ and separation between them is $\displaystyle l$. A constant magnetic field $\displaystyle B$ perpendicular to the plane of the loop exists in the entire space. A rod $\displaystyle C D$ of length $\displaystyle L(L>l)$ and mass $\displaystyle m$ is made to slide down from rest under the gravity as shown in figure. The terminal speed acquired by the rod is $\displaystyle \_\_\_\_$ m/s. (g = acceleration due to gravity)