Three charges ( +q,+2 q ) and ( +4 q ) are connected by strings as shown in the figure. What is ratio of
tensions in the strings ( mathrm{AB} ) and ( mathrm{BC} ).
(A) 1: 2
(B) 1: 3
( (mathrm{C}) 2: 1 )
(D) 3: 1

( begin{aligned} T_{2}=& frac{K(4 q) q}{(2 d)^{2}}+frac{K(2 q)(4 q)}{d L} T_{1}=& frac{2 K q^{2}}{d^{2}}+frac{K q^{2}}{d^{2}} &=frac{3 K q^{2}}{d^{2}} T_{2}=& frac{K q^{2}}{d^{2}}+frac{8 K q^{2}}{d 2} =& frac{9 K q}{d L} T_{1}: T_{2} & & 1: 3 end{aligned} )