The electric field on the conductor defines the effect of static.

    Examples

        The electric field from A insulator makes the electrons of B conductor move towards the surface of A looking at B. These electrons make up the bound induced charge.Unless B isn?t in the electric field from A, the movement of charges doesn?t occur. The free induced charge (positive) creates an electric field outside of B, with the field lines eventually terminating on some grounded object. If this field is integrated from B to a ground point, we will get a positive figure, which, by definition, is the voltage of B. Thus we have an uncharged conductor with a positive voltage.

Figure 1. Insulated conductor in the field from a charged insulator

        The condition in Figure 2?de is the same as im Figure 1 .But the conductor is grounded.Thus, the voltage of B is zero.But, B has negative charge at the bound. If the ground connection is broken, and B is moved away from the neighborhood of A (in an insulated way), B will still have its negative charge, giving B a negative voltage.Consequently, B is charged by induction.

Figure 2. Grounded conductor in the field from a charged insulator

        In figure 3 an operator holding a positively charged insulative material is standing on an insulating floor. The charge from the material will bind a negative charge on the operator by induction. A positive charge of the same numerical magnitude as the negative charge will cause the operator to have a positive voltage. The field lines from the operator's positive charge will run through the floor covering to the grounded underlayer.

Figure 3. Insulated operator handling a charged piece of insulative material

In figure 4 there is a hazardous induction event. Operator is pouring powder from a plastic bag into a tank containing explosive vapors. At the beginnig the operator who is not grounded ,has no charge.But the plastic bag gives him some charge and generate a positive voltage. If operator accidentally touches the tank, a spark discharge occurs, resulting in an explosion that hurts the operator badly.

Figure 4. Ungrounded operator handling insulative materials in an unsafe environment