Two small, negatively charged plastic spheres are placed near a neutral iron block, as shown in Figure 14.89. Which arrow (a–j) in Figure 14.89 best indicates the direction of the net electric field at location A?

The charge redistribution is referred to as the process in which charge flows from a higher charged to a lower charged particle in order to redistribute the charges.

The concept of the charge redistribution gives the direction of the net electric field at location A.

As the two negatively charged plastic sphere caomes in contact with the neutral block of iron, charge distribution starts to occur. Moreover, the neutral block of iron also produces an equal force on the charged particle. However, as both blocks and the spheres are exerting force on each other, then arrow (f) represents the direction of the resultant or the net electric field at location A and has a magnitude of zero.

The other arrows apart from (f) do not show the direction of the net electric field as they are in other directions and the electric field cannot go in the other direction due to the charge redistribution.

Thus, the arrow (f) indicates the direction of the net electric field at location A.