Question

2. In the figure below the five wires all carry a current of 5 amps. Calculate the magnitude and direction of the force on: (a) wire 1 from the other 4 wires (b) wire 2 from the other 4 wires (c) wire 3 from the other 4 wires (d) wire 4 from the other 4 wires (e) wire 5 from the other 4 wires O kde dle-de-d-

Answer 1

force between two infinitely long wire is given by fa lo I, 2 N/m. Here F is force per mit length and it is repulsive if direction of current in both wire is opposite and it is attractive if direction is same. Thus force on wire I from all other 4 wires f = to I² llo I² elo I2 elo I² and 22 (20) 22(30) 2x(40) here current in all the wires is equal to I = 5 A and all will attract wired towards right F 2 4XX10 71²/1 + b 2 + 7 + 4) and ax 10*7x53 ( 12 +6+4+3) - sox lot x 25 = 1:04X10 N/m (b) force on wire 2 to 12 2x (3d) -re sign means wire I will attract wire 2 toweeds left and we are taking right as the of a lot (2 + 1) = - = = 4.17X106 Nm of llo 72 2 2 loz² 22/200) . aadaad X 270 x TO 4 XX10

© for force on wire 3 lo 2 lo I2 do 72 (27(20) and taadaa(2d)) Now wire t and wire are attracting wire 3 from left f = 0 N/m (d) force on wire 4 f =-/ Mo I210 I2 - to 12 elo I2 (30) 20(20) + aad) + Qad -4.17 x are sign means direction is towards left. (e) force on wires llo I² lo I2 ) (44) 27(3107(2) = -1.04x10s N/m