question_answer

Three point charges are placed at the comers of an equilateral triangle. Assuming only electrostatic forces are acting. Then the system:

A)  will be in equilibrium if the charges rotate about the centre of the triangle

B)  can never be in equilibrium

C)   will be in equilibrium if the charges have the same magnitudes but different signs

D)  will be in equilibrium if the charges have  different magnitude and different signs.

Correct Answer: B

Solution :

Horizontal force cancil out at A and and C \[{{F}_{\upsilon }}\]at \[A=2F\sin 60\] \[{{F}_{\upsilon }}\]at \[B=F\sin 60\] \[{{F}_{\upsilon }}\]at\[C=F\sin 60\]and point AB and C forces acts hence no equilibrium.