4.
在直角坐标系\(xOy\)中,曲线\(C\)的方程为:\((x-1)^{2}+y^{2}=1\)以\(O\)为极点,\(x\)轴的非负半轴为极轴建立极坐标系.
\((\)Ⅰ\()\)求曲线\(C\)的极坐标方程;
\((\)Ⅱ\()\)直线\(l_{1}\)的极坐标方程是\(2ρ\sin (θ+ \dfrac {π}{3})+3 \sqrt {3}=0\),直线\(l_{2}\):\(θ= \dfrac {π}{3}(ρ∈R)\)与曲线\(C\)交于\(O\)、\(P\)两点,与直线\(l_{1}\)的交于点\(Q\),求线段\(PQ\)的长.