Question

Three point charges, -4.7 x 10-9 C, -9.7 x 10-9 C, and 7.2 x 10-9 C, are fixed at different positions on a circle. The total electric potential at the center of the circle is -1900 V. What is the radius of the circle

Answer 1

Step-by-step explanation:

q1 = - 4.7 x 10^-9 C

q2 = - 9.7 x 10^-9 C

q3 = 7.2 x 10^-9 C

Potential at the centre of the circle, V = - 1900 V

Let the radius of the circle is r.

So, the potential is given by

`V = (Kq_(1))/(r)+(Kq_(2))/(r)+(Kq_(3))/(r)`

`- 1900 = (9* 10^(9))/(r)\left ( - 4.7 - 9.7 + 7.2 \right )* 10^(-9)`

`- 1900 = (-9* 7.2)/(r)`

r = 0.034 m = 3.4 cm