Question 472: Electrostatics & Capacitance

Question

Three charges Q, + q and + q are placed at the vertices of a right-angle isosceles triangle as shown below. The net electrostatic energy of the configuration is zero, if the value of Q is :

Accepted Answer

U = K$$\left[ {{{{q^2}} \over a} + {{Qq} \over a} + {{Qq} \over {a\sqrt 2 }}} \right] = 0$$
$$ \Rightarrow $$  q = $$-$$ Q$$\left[ {1 + {1 \over {\sqrt 2 }}} \right]$$
$$ \Rightarrow $$  Q = $${{ - q\sqrt 2 } \over {\sqrt 2  + 1}}$$

Answer

$${{ - q} \over {1 + \sqrt 2 }}$$

Answer

+ q

Answer

$$-$$ 2q

Answer

$${{ - \sqrt 2 q} \over {\sqrt 2  + 1}}$$

Electrostatics & Capacitance

Three charges Q, + q and + q are placed at the vertices of a right-angle isosceles triangle as shown below. The net electrostatic energy of the configuration is zero, if the value of Q is :

Choose the correct answer: