[" Three point charges "q,-4q" and "2q" are placed at the vertices of an "],[" equilateral triangle "ABC" of side "l" as shown in the figure.Obtain "],[" the expression for the magnitude of the resultant electric force "],[" acting on the charge "q" ."]

Two point charges +q and -2q are placed at the vertices B and C of an equilateral triangle ABC of side a as given in the figure. Obtain the expression for (i) The magnitude and (ii) the direction of the resultant electric field at the vertex A due to these two charges.

Three charges Q, (+q) and (+q) are placed at the vertices of an equilateral triangle of side l as shown in the figure. It the net electrostatic energy of the system is zero, then Q is equal to

Three charges Q, (+q) and (+q) are placed at the vertices of an equilateral triangle of side l as shown in the figure. It the net electrostatic energy of the system is zero, then Q is equal to

Three charges Q, (+q) and (+q) are placed at the vertices of an equilateral triangle of side l as shown in the figure. It the net electrostatic energy of the system is zero, then Q is equal to

Three point charges each equal to q are placed on the vertices of an equilateral triangle of side l. The potential energy of the system is