Question

A negative point charge q1 = 25 nC is located on the y axis at y = 0 and a positive point charge q2 = 10 nC is located at y =14 cm. Find the y coordinate of the points where the net electric potential due to these two charges is zero.

Answer 1

Answer:

 y = 0.1 m

Explanation:

The electrical power for point loads is

         V = $k \sum \frac{q_i}{r_i}$k Sum qi / ri

in this case

         V = k ($- \frac{q_1}{r_1 } + \frac{q_2}{r_2}$)

indicate that V = 0

        $\frac{q_1}{r_1} = \frac{q_2}{r_2}$

        r₂ = $\frac{q_2}{q_1} r_1$

the distance r1 is

         r₁ = y -0

the distance r2

         r₂ = 0.14 -y

we substitute

       

        0.14 - y = $\frac{10}{25}$  y

          y ( $\frac{10}{25} + 1$) = 0.14

          y 1.4 = 0.14

          y = 0.14 / 1.4

          y = 0.1 m