Question

Two point charges of 20muC and 80muC are placed apart . Find the positive where the electric field is Zero​

Answer 1

Explanation:

The electric filed is zero at 6 cm from 20 micro coulomb charge.

Explanation:

Given that,

First point charge q_{1}= 20\times10^{-6}

Second point charge q_{2}= 80\times10^{-6}

Distance d = 18 cm

let x cm from 20 micro coulomb electric field would be zero.

According to the formula,

The electric field from a point charge 20 micro coulomb at point C.

E_{1}=\dfrac{k\timex 20\times 10^{-6}}{x^2}

The electric field from a point charge 80 micro coulomb at point C.

E_{2}=\dfrac{k\timex 80\times 10^{-6}}{(18-x)^2}

Net electric field at point C is zero

Thus, E_1=E_2

\dfrac{k\timex 20\times 10^{-6}}{x^2}=\dfrac{k\timex 80\times 10^{-6}}{(18-x)^2}

\dfrac{1}{x^2}=\dfrac{4}{(18-x)^2}

18-x=2x

x=6