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NEET 2022 Physics and Chemistry
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© examsnet.com
Question : 32
Total: 100
A copper wire of length
10
m
and radius
(
10
−
2
√
π
)
m
has electrical resistance of
10
Ω
. The current density in the wire for an electric field strength of
10
(
V
∕
m
)
is
[NEET-2022]
10
4
A
∕
m
2
10
6
A
∕
m
2
10
−
5
A
∕
m
2
10
5
A
∕
m
2
Validate
Solution:
👈: Video Solution
Resistance,
R
=
ρ
L
A
=
L
σ
A
⇒
σ
=
L
R
A
Also current density
j
=
σ
E
=
L
E
R
A
j
=
10
×
10
10
×
π
(
10
−
2
√
π
)
2
=
100
10
×
π
×
(
10
−
4
π
)
=
10
5
A
∕
m
2
© examsnet.com
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