2. +q, +2q, +3q, +4q, ……(up to +20q) charges are situated at coordinates (0,0) , (1,0) ,(2,0) , ….. (Up to 20). What is the total charge stored in the system? a) +20q b) +210q c) +420q d) +190q
Answer: b Explanation: As charge is additive, total charge will be (1+2+3+4+…. +20)*q=20∗212*q= 210q. But if the polarities of the charges are different i.e. some of them are positive and some are negative, then the result will be different. We have to add separately the positive charges and the negative charges.
