Two charges 4μCand−4μC are placed at (−3,0,0)and(3,0,0) cm respectively in an external field given by E = (9×10⁶) / (r²)Cm⁻² , Find the energy of the system in this external field.
a. -2.4 J
b. 2.4 J
c. 0
d. -1.4 J