Question 871: Electrostats & Capacitance

Question

Three charges $$-\mathrm{q}, \mathrm{Q}$$ and $$-\mathrm{q}$$ are placed at equal distances on a straight line. If the total potential energy of the system of three charges is zero then the ratio $$\frac{Q}{q}$$ is

Accepted Answer

Potential energy of the system is zero.
$$\begin{aligned}
& 	herefore \frac{1}{4 \pi \varepsilon_0}\left(\frac{-q \cdot Q}{x}+\frac{-q \cdot Q+}{x}+\frac{(-q)(-q)}{2 x}ight)=0 \
& 	herefore-2 q Q+\frac{q^2}{2}=0 \
& 	ext { or }-2 Q+\frac{q^2}{2 x}=0 \quad 	herefore 2 Q=\frac{q}{2} 	ext { or } \frac{Q}{q}=\frac{1}{4}
\end{aligned}$$

Answer

$$1: 2$$

Answer

$$1: 1$$

Answer

$$1: 4$$

Answer

$$1: 3$$

Electrostats & Capacitance

Three charges $-\mathrm{q}, \mathrm{Q} and -\mathrm{q} are placed at equal distances on a straight line. If the total potential energy of the system of three charges is zero then the ratio \frac{Q}{q}$ is

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