Object A, B and C, are three identical, insulated, spherical conductors. Originally, A and B have charges of +3 mC, whereas C has a charge of -6mC. Objects A and C are touched and moved apart, Objects B and C are touched before they moved apart.
(i) If pbjects A and B are now held near each other they will
(a) attract (b) repel (c ) have no effect on each other.
(ii) If instead object A and C held near each other, they will
(a) attract (b) repel (c ) have no effect on each other.

Explanation

Initially
* when the object A and C are allowed to touch and then moved aparts,

`[+3mC+(-6mC)= -3]-(3)/(2)mC -(3)/(2)mC`
* When the object B and C are allowed to touch and then moved apart:

`[+3mC+(-(3)/(2)mc)=+(3)/(2)mC]+(3)/(4)mC +(3)/(4)mC`
(i) Hence, if A and B are now held near each other. They will attract each other.
(ii) If A and C are now held near each other, they will also attract each other.