Figure shows two parallel wires separated by a distance of 4.0 cm and carrying equal currents of 10A along opposite directions. Find the magnitude of the magnetic field B at the points `A_1, A_2, A_3 and A_4.`

Explanation

Magnitude of magnetic field at `A_1` `B =(2xx10^(-7)xx10)/(2xx10^(-2) - (2xx10^(-7)xx10)/(6xx10^(-2)` `
`. `= ((1 - (1)/(3))xx10^(-4) T`
`. `=0.67xx10^(-4) T`
`. Magnetic field at `A_2`. `B= (2xx10^(-7)xx10)/(1xx10^(-2) + (2xx10^(-7) xx10)/(3xx10^(-2)`
`. `= (8)/(3) xx 10^(-4) T`
`.`=2.67xx10^(-4)T`
`. Magnetic field at `A_4` `B=sqrt(((2xx10^(-7)xx10)/(2sqrt2xx10^(-2)))^2 + ((2xx10^(-7)xx10)/(2sqrt2xx10^(-2)))^2` `
`. `=1xx10^(-4)T.`