Question

In Figure 16.58, what is the direction of the electric field? Is ∆V = Vf −Vi positive or negative?

Short answer

The direction of the electric field is towards the ball and the potential difference is negative.

Step-by-step solution

Concept/Significance of the potential difference.

A potential difference is the amount of work required to move a charge from one location in the electric field to another.

It refers to the amount of labour or energy necessary to move an electron in a circuit or a specific spatial area of the electrical field.

Determination of the direction of the electric field and sign of the potential difference.

The electric field always points from the positive charge to the negative charge. As shown in figure 16.58, thecharges on the ball are negative. it means the electric field is towards the ball.

The positive side has higher potential energy than the negative side. So, the potential difference which is given by,

$∆V=V_f-V_i$is negative as the potential is directed to the negative charges on the ball.

Thus, the direction of the electric field is towards the ball, and the potential difference is negative.