Question

2 Ω resistance coil is to be constructed from a constantan wire of diameter 0.0315 cm.
If the resistivity of constant an is 49x10^(-6) Ωcm, find the length of wire required to construct the coil.

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Answer 1

Explanation:

Answer

Given, Diameter=0.5mm,resistivity=1.6×10

−8

Ω−m,resistance=10Ω

we know that R=ρ

A

1

⇒1=

ρ

RA

Where A is the area of the cross-section,

=

1.6×10

−8

10×3.14×(

2

0.0005

)

2

=122.7m

Thus the length of the wire is 122.7m