ل/E=K q/d^2 =(9*〖10〗^9 *4.2*〖10〗^(-6))/〖(1.2)〗^2 =(9*4.2*〖10〗^3)/1.44 =(9*42*〖10〗^2)/(144*〖10〗^(-2) ) =(378*〖10〗^4)/144 E=2.62*〖10〗^4 N/C