Question

a copper wire has a diameter 0.5mm and resistivity 1.6×10-⁸ohm meter .what will be the length of this wire to make the resistance 12ohm?.how much will it be the resistance of another copper wire same length but half the diagram?​

Answer 1

Answer:



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Class 12

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>>Ohm's Law

>>What length of copper wire of resistivit

Question



What length of copper wire of resistivity 1.7×10−8Ωm and  radius 1 mm is required so that its resistance is 1Ω?

A

184.7m

B

200m

C

190.5m

D

150m

Medium

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Solution



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Correct option is A)

Step 1: The resistance of wire is expressed as  

R=AρL                                      ....(1)

Given, R=1Ω,

The area of cross section, A=πr2=3.14×0.0012=3.14×10−6.

Resistivity ρ=1.7×10−8 ohm-meter

Step 2: Putting above values in equation (1)

We get

 1=3.14×10−61.7×10−8×L 

⇒L=1.7×10−81×3.14×10−6=1.7×10−83.14×10

Explanation:

Please mark me as the brainliest because i have triend 42 times to write this.

Answer 2

Answer:

since the data is given as

resistivity, diameter and resistance so i have done this step by step