A long wire carrying a 5.5 A current perpendicular to the xy-plane intersects the x-axis at x=−2.0cm . A second, parallel wire carrying a 2.5 A current intersects the x-axis at x=+2.0cm . Part A At what point on the x-axis is the magnetic field zero if the two currents are in the same direction? Express your answer in centimeters. x x = nothing cm SubmitRequest Answer Part B At what point on the x-axis is the magnetic field zero if the two currents are in opposite directions? Express your answer in centimeters. x x = nothing cm SubmitRequest Answer Provide Feedback Next

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Answer:

a

The point on the x-axis where the magnetic field will be zero is  [tex] d =  2.8 \ cm [/tex]

b

The point on the x-axis where the magnetic field will be zero is [tex]Z =  5.333 \  cm [/tex]Explanation:

From the question we are told that

   The first  current is [tex]I_1 = 5.5 \ A[/tex]

    The point of x- axis  intersection is  [tex]x =  -2.0 \  cm[/tex]

    The second current is  [tex]I_2  =  2.5  \  A[/tex]

     The point of intersection of the x-axis is  [tex]x =  2 .0  \  cm[/tex]

Generally given that the current of the two wires are same direction it means that the magnetic field in -between the wires will cancel out  giving zero

 So  

       [tex]B_1 -  B_2 =  0[/tex]

=>     [tex]B_1  =  B_2 [/tex]

=>      [tex]\frac{\mu_o *  I_1 }{2 *  \pi *  d }  = \frac{\mu_o *  I_2 }{2 *  \pi *  (4 -d) }[/tex]

Here  d is the of one wire to the point where the magnetic field is 0

and  given that the total distance in-between the wire is  D  =  2 =  2 =  4

Hence the distance of the other wire to the point where magnetic field is zero is  (4 - d)

So

     [tex]\frac{5.5}{ d}  =  \frac{2.5}{4-d}[/tex]

=>   [tex] 8d  =  22 [/tex]

=>   [tex] d =  2.8 \ cm [/tex]

So the point on the x-axis where the magnetic field will be zero is  [tex] d =  2.8  [/tex]

 Generally given that the current of the two wires are opposition direction it means that the magnetic field at a position which is not in-between the wire will be zero  

Let that position be  k

Let  the distance from the middle of both wires to k  be Z  

So

      [tex]\frac{\mu_o *  I_1 }{2 *  \pi *  ( 2 +  Z) }  = \frac{\mu_o *  I_2 }{2 *  \pi *  (Z -2) }[/tex]

=>  [tex]5.5 Z  - 11 =  5+ 2.5 Z[/tex]

=>    [tex]3Z  =  16[/tex]

=>    [tex]Z =  5.333\  cm[/tex]