Given radius of the sphere r = 14 cm =14*10-2 m charge on the sphere q = 6*10-7 C electric field on the spheresurface E = k q / r2 = (9*109 * 6*10-7 C /(14*10-2 )2 = 27 .55*104 N /C electric potential at spheresurface V = k q / r = (9*109 * 6*10-7 C /(14*10-2 ) = 3.85*104 V V = 500V V = k q / r = (9*109 )* 6*10-7 C /(r r = (9*109* 6*10-7 C / 500 = 10.8 m = (9*109 * 6*10-7 C /(14*10-2 ) = 3.85*104 V V = 500V V = k q / r = (9*109 )* 6*10-7 C /(r r = (9*109* 6*10-7 C / 500 = 10.8 m = (9*109 )* 6*10-7 C /(r r = (9*109* 6*10-7 C / 500 = 10.8 m