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Physics
The magnetic force between wires as shown in figure is <img class=img-fluid question-image alt=image src=https://cdn.tardigrade.in/img/question/physics/6f92510fe87375960743988b74e5e934-.png />
Q. The magnetic force between wires as shown in figure is
1749
240
Moving Charges and Magnetism
Report Error
A
2
π
μ
0
i
I
2
ℓ
n
(
2
x
x
+
ℓ
)
19%
B
2
π
μ
0
i
I
2
ℓ
n
(
2
x
2
x
+
ℓ
)
16%
C
2
π
μ
0
i
I
ln
(
x
x
+
ℓ
)
44%
D
None of these
21%
Solution:
Magnetic field at
d
r
,
B
=
2
π
r
μ
0
I
Force on small element at a distance
r
of wire of length
1 is
d
F
=
i
(
d
r
)
(
2
π
r
μ
0
I
)
F
=
2
π
μ
0
i
I
x
∫
x
+
ℓ
r
d
r
=
2
π
μ
0
i
I
ℓ
n
(
x
x
+
ℓ
)