Question

Question #cc69d

Answer 1

`9.44*10^-3Wbcolor(white)(l)s^-1`

Explanation:

From Faraday's law, we know that:
`(dNphi)/(dt)proptoV`

We also know that `V=IR`

Given resistivity, we also know that:
`R=(rhol)/A`

Combing these gives us:
`(dNphi)/(dt)propto(Irhol)/A`

`rho=1.97*10^-8Omegam`
`I=8.9A`

`l=2pir=pi*9.1/100=(91pi)/1000m`
`A=pir^2=pi(2.6/2000)^2=pi(1.69*10^-6)m^2`

`(dNphi)/(dt)propto(8.9(1.97*10^-8)((91pi)/1000))/(pi(1.69*10^-6))=9.44*10^-3Wbcolor(white)(l)s^-1`

The magnetic field must change at a rate of `9.44*10^-3` Webers per second.