The horizontal component of earth's magnetic field at a certain place is ` 3xx 10^(-5) T` and the direction of the field is from the geographic south to the geographic north. A very long straight conductor is carrying a steady current of 1 A. What is the force per unit length on it when it is placed on a horizontal table and the direction of current is from east to west ?

Explanation

Here `B = 3 xx 10^(-5)T`
`i = 1A`
when the current is flowing from east to west and magnetic field is from south to north `theta = 90^(@) F = Bil sin theta`
`= 3 xx 10^(-5) xx l xx sin 90^(@)`
`rArr (F)/(l) = 3 xx 10^(-5)N` (downward)