Three charges `2.0 * 10^-6 C, 3.0 *10^-6 C` and `4.0 * 10^-6 C` are placed at the three corners A, B. C of an equilateral triangle of side 20 cm. Find the force on the charge at C due to the rest two.

Three charges, each equal to 16 * 10^-9 C are placed at the three corners of a square of side 4 cm. Find the electric field at fourth corner.

Two charges each of magnitude 4muC are placed at two corners of an equilateral triangle of side 4m. Find the magnitude of electric field at the third corner.

ABCD is a square of side 20 cm positive charges of +2 * 10^-9 C. +4 * 10^-9 C and + 8 * 10^-9 C are placed at the corners A, B and C respectively. Calculate the work required to be done to transfer a unit positive charge from D to the point of intersection of the diagonals.

Four point charges q, -q, 2q and - 2q are placed at the comers of a square of side 5 cm. If q= 5 * 10^-6 C , find the magnitude of the electric field at the intersection of the diagonals.

Two charges of 5 * 10^-6 C and -5 * 10^-6 C are placed 5 cm apart, at points A and B respectively. Find the electric field at C, 5 cm away from both A and B.

If three points (0,0), (-3,-6) and (3,x) form an equilateral triangle then the value of x will be __- a)2 b)-3 c)-4 d)None of these