Two linear parallel conductors carrying currents in the same direction attract each other and two linear parallel conductors carrying currents in opposite direction repel each other. The force acting per unit length due to currents `I_1` and `I_2` in two linear parallel conductors held distance r apart in vacuum in SI unit is `F=(mu_0)/(4pi)(2I_1I_2)/(r)`
Read the above passage and answer the following questions:
(i) What is the basic reason for the force between two linear parallel conductors carrying currents?
(ii) Two straight wires A and B of lengths `2cm` and `20cm`, carrying currents `2*0A` and `5*0A` respectively in opposite directions are lying parallel to each other `4*0cm` apart. The wire A is held near the middle of wire B. What is the force on `20cm` long wire B?
(iii) What does this study imply in day to day life?