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

Answer:

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

$V = \frac{Kq_{1}}{r}+\frac{Kq_{2}}{r}+\frac{Kq_{3}}{r}$

$- 1900 = \frac{9\times 10^{9}}{r}\left ( - 4.7 - 9.7 + 7.2 \right )\times 10^{-9}$

$- 1900 = \frac{-9\times 7.2}{r}$

r = 0.034 m = 3.4 cm