Question

two long parallel wires are placed at a distance of 16 cm from each other in air each wire has a current of 4 ampere calculate the magnetic field at midpoint between them when the current in them are in same direction and in opposite direction

Answer 1

Answer:

1 × 10 ^-5

Explanation:

Answer 2

Answer:

when current is in same direction M.F is

$\frac{\mu_{0}I }{8\pi }$

when current is in opposite direction M.F is

0

Explanation:

we know that a  current carrying wire generates magnetic field .

We are given two long parallel current carrying wire, so magnetic field generated by a single long current carrying wire is given as follows

     $B = \frac{\mu _{0}I }{2\pi r}$

where $\mu_{0}$ = permeability

           r= distance where M.F has to be calculated

           I = current in the wire

Given : current = 4 A

           : distance between wire

Case 1:  when current is in same direction

      M. F due to first wire at mid point between two wires

        $B_{1} = \frac{\mu_{0}I }{2\pi r}$

       M. F due to second wire at mid point between two wires

       $B_{2} = \frac{\mu_{0}I }{2\pi r}$

so total M.F at  distance 8 cm is

    B = B₁ + B₂

    $\frac{\mu_{0}I }{2\pi r} + \frac{\mu_{0}I }{2\pi r} \\\\2\times \frac{\mu_{0}I }{2\pi \times 8} \\\\ \frac{\mu_{0}I }{8\pi }$

Case 2 :  when current is in opposite direction

M. F due to first wire at mid point between two wires

$B_{1} = \frac{\mu_{0}I }{2\pi r}$

M. F due to second wire at mid point between two wires

$B_{2} = -\frac{\mu_{0}I }{2\pi r}$

so total M.F at  distance 8 cm is

B = B₁ + B₂

$\frac{\mu_{0}I }{2\pi r}-\frac{\mu_{0}I }{2\pi r} \\\\\\0$

Hence total M.F is calculated in both the cases

when current is in same direction M.F is

$\frac{\mu_{0}I }{8\pi }$

when current is in opposite direction M.F is

0