Question

a current of 10 A flows downwards in a long straight wire vertical conductor and the earth's horizontal flux density is 2*10^-7 T . The neutral point occurs at:


Pls help as soon as possible ​

Answer 1

HELLO DEAR,

GIVEN:-

magnetic field due to earth or flux density = 2 × 10^(-7)T

I =10A

I =10Aμo = 4π × 10^(-7) H/m

and at neutral point net magnetic field = 0

also, magnetic field due to infinite wire = μoi/2πr

so magnetic field due to wire = magnetic field due to earth

=> μo10/2πr = 2 × 10^(-7)

=> {4π × 10^(-7) × 10}/2πr = 2 × 10^(-7)

=> 4πr = 4π × 10

=> r = 10m

therefore,

It will be due east 10m from the wire .

because in the east direction ,

magnetic field lines due to wire will be running in opposite direction of magnetic field due to earth so both will cancel each other.

I HOPE IT'S HELP YOU DEAR,

THANKS