The fundamental forces in decreasing order of their magnitude are, strong nuclear force $\left(1\right)>$the electromagnetic force $({10}^{-2} )>$ weak nuclear force $\left({10}^{-13}\right)>$ gravitational force $\left({10}^{-49}\right)$. So, the relation between electromagnetic force and weak nuclear force is, 
$\frac{E}{W}=\frac{{10}^{-2}}{{10}^{-13}}={10}^{11}$.