Six point charges are kept 60° apart from each other on the circumference of a circle of radius R as shown in figure. The net electric field at the centre of the circle i $s ________.$
(ε₀ is permittivity of free space)

Question

Six point charges are kept 60° apart from each other on the circumference of a circle of radius R as shown in figure. The net electric field at the centre of the circle i $s ________.$

(ε₀ is permittivity of free space)

G1 Physics · Accepted Answer

Imagine first that all six equally spaced charges are +Q. Because of complete symmetry, the net electric field at the centre would then be zero. In the actual arrangement, the charge at the upper-left position is -Q instead of +Q. Changing +Q to -Q is equivalent to adding an extra charge -2Q at that position to the symmetric zero-field arrangement. The field magnitude at the centre due to this effective charge is E = 2kQ/R². The position of the negative charge is at 150° measured from +x. Becau…

Six point charges are kept 60° apart from each other on the circumference of a circle of radius R as shown in figure. The net electric field at the centre of the circle i s ________. (ε₀ is permittivity of free space)