Answer
Please see the work below.
Work Step by Step
(a) We know that if both charges are like charges then the direction of the electric field due to each charge will be in the opposite direction along the line joining the two charges. Thus, there be a possibility of identifying a point between the charges where the net electric field is zero and hence the zero field point between the charges is possible only when the charges are of the same sign.
(b) We know that the electric field due to a charge is proportional to the magnitude of the charge. This means that the larger the magnitude of the charge, the greater will be the field or vice versa. We are given that the net field is vanishing at a point closer to charge 1. Thus, the electric field due to charge 1 is extended to less distance than that of charge 2. We can conclude that charge 1 has less magnitude as compared to that of charge 2.
