Question

A copper wire has a diameter of 0.5 mm and resistivity of 1.6 x 10–8 ohm m. What will

be the length of this wire to make its resistance 10ohm? How much does the

resistance change if the diameter is doubled?
will defenitely mark as brainliest if explained step wise​

Answer 1

R=pl/A

p-resistivity

R- resistance

d-diameter=0.5mm=1/2×10^-3m

r-radius=1/4×10-3m=0.25×10^-3m

R=pl/πr²

R1/R2=p1/p2×r2²/r1²

p1=p2

d1/d2=r1×2/r2×2=r1/r2

r2=2r1

r2/r1=2

10/R2=4

R2=10/4=2.5 ohm

I hope this helps ( ╹▽╹ )

Answer 2

Answer:

Here are the answers!!

Explanation:

Refer attachment for explanation!!!