Dr Gulshan S. answered 07/23/20
Physics Teaching is my EXPERTISE with assured improvement
Total current is rate of flow of charge
The conventional is rate of flow of positive charge and opposite to the direction of flow of negative charge
In this case3 positive ions are moving to right at he rate of 4.5*1019 per min
So corresponding current to the right = 3*1.6*10-19 *4.5*1019 / 60 Amp ( charge per sec)
Charge of each proton= charge of each electron = 1.6*10-19 C
now for electrons moving to the left current is in the right direction
Current due to electrons = 2* 1.6*10-19*2.5* 1020/60 Amp
The currents being in the same directction are added
Hence net current is sum of the two currents ( right Direction)