Question

Question #b8ad5

Answer 1

0.2377 `Omega`

Explanation:

To find the resistance of a copper wire with given parameters we use
`R=(rho*l)/A`
`(1.68*10^(-8)*25)/(3.14*5.627*10^(-7))=0.2377Omega`

According to your confusion ..
we got diameter=1.5mm which is equal to `0.0015 m`
but in scientific notion we write it `1.5*10^(-3)m`
Dividing it by 2 we get ..
`0.75*10^(-3)m=7.5*10^(-4)m`