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:

Step 1: The resistance of wire is expressed as

R=

A

ρL

....(1)

Given, R=1Ω,

The area of cross section, A=πr

2

=3.14×0.001

2

=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

−6

1.7×10

−8

×L

⇒L=

1.7×10

−8

1×3.14×10

−6

=

1.7×10

−8

3.14×10

−6

=1.847×10

2

m.

Therefore, the length of the wire is 184.7 meters.

Explanation:

MARK AS BRAINLIST