5.
如图,\(M\)、\(N\)和\(P\)是以\(MN\)为直径的半圆弧上的三点,\(O\)点为半圆弧的圆心,\(∠\)\(MOP\)\(=60^{\circ}\),电荷量相等、符号相反的两个点电荷分别置于\(M\)、\(N\)两点,这时\(O\)点电场强度的大小为\(E\)\({\,\!}_{1}\);若将\(N\)点处的点电荷移至\(P\)点,则\(O\)点的场强大小变为\(E\)\({\,\!}_{2}\),\(E\)\({\,\!}_{1}\)与\(E\)\({\,\!}_{2}\)之比为\((\) \()\)