iran-konkur 2020 Q180

iran-konkur · Other · konkur-riazi_1399_specialized_old-curriculum Not Maths
180. In the figure below, the resultant electric force on each of the charges is zero. The ratios $\dfrac{q_3}{q_2}$ and $\dfrac{x}{r}$ from right to left are:
[Figure: Three charges on a line: $q_2$, then $q_3$ at distance $x$, then $q_1 = -\dfrac{4}{5}q_2$ at distance $r$]
(1) $9\ ,\ \dfrac{3}{2}$ (2) $-9\ ,\ \dfrac{3}{2}$ (3) $9\ ,\ 2$ (4) $-9\ ,\ 2$
\textbf{180.} In the figure below, the resultant electric force on each of the charges is zero. The ratios $\dfrac{q_3}{q_2}$ and $\dfrac{x}{r}$ from right to left are:

\textit{[Figure: Three charges on a line: $q_2$, then $q_3$ at distance $x$, then $q_1 = -\dfrac{4}{5}q_2$ at distance $r$]}

(1) $9\ ,\ \dfrac{3}{2}$ \quad (2) $-9\ ,\ \dfrac{3}{2}$ \quad (3) $9\ ,\ 2$ \quad (4) $-9\ ,\ 2$