Find the resistivity of the resistive wire

[Fatima Hasan]

Homework Statement

Homework Equations

$ρ=\frac{RA}{L}$
$I=\frac{ΔQ}{Δt}$
$I=\frac{ΔV}{R}$

The Attempt at a Solution

(a)
$ρ=\frac{RA}{L}$
$L=\frac{2*π*r}{2} = πr$
ρ = (5*2.5*10^-7)/(π*0.1)
ρ = 4*10^-6 Ωm.

(b)
R_eq = 7+5 = 12Ω
$I=\frac{ΔV}{R}$
I = 36/12 = 3 A
$I=\frac{ΔQ}{Δt}$
3 = ΔQ / 100
ΔQ = 3*100 = 300 C

Is my answer correct ?

 

[cnh1995]

Homework Statement

View attachment 225595

Homework Equations

$ρ=\frac{RA}{L}$
$I=\frac{ΔQ}{Δt}$
$I=\frac{ΔV}{R}$

The Attempt at a Solution

(a)
$ρ=\frac{RA}{L}$
$L=\frac{2*π*r}{2} = πr$
ρ = (5*2.5*10^-7)/(π*0.1)
ρ = 4*10^-6 Ωm.

(b)
R_eq = 7+5 = 12Ω
$I=\frac{ΔV}{R}$
I = 36/12 = 3 A
$I=\frac{ΔQ}{Δt}$
3 = ΔQ / 100
ΔQ = 3*100 = 300 C

Is my answer correct ?

Yes, but the resistivity comes out to be 3.978×10^-6 ohm-meter. You might not get full credit if you round that off to 4.