Question

When 5V potential difference is applied across a wire of length 0.1, the drift speed of electrons is 2.5× 10-4m/s if the electron density in the wire is 8× 1028m-3, calculate the resistivity of the material of wire.

Answer 1

resistivity of the material of wire is 1.6 × 10^-5

potential difference applied across wire, V = 5 volts

length of wire, l = 0.1 m

drift velocity, vd = 2.5 × 10^-4 m/s

electron density in the wire, n = 8 × 10^28 /m³

charge on electron, e = 1.6 × 10^-19 C

using formula, i = neAvd .......(1)

from Ohm's law, i = V/R ......(2)

and R = ρl/A......(3)

so,from equations (1), (2) and (3) we get

V/ρl = nevd

⇒ρ = V/nevd.l

= 5/(8 × 10^28 × 1.6 × 10^-19 × 2.5 × 10^-4 × 0.1)

= 5/(8 × 1.6 × 2.5 × 10⁴)

= 5/(20 × 1.6 × 10⁴)

= (1/6.4) × 10-⁴

≈ 1.6 × 10^-5 Ωm

also read similar questions : a potential difference of 5v is applied across a conductor of length 10cm. If drift velocity of electrons is 2.5x 10*-4 ...

https://brainly.in/question/11371091

A potential difference of V volts is applied across the ends of a copper wire of diameter D and length l. What will be t...

https://brainly.in/question/354565

Answer 2

$\huge\star\mathfrak\blue{{Answer:-}}$

1.6 x10-5 Ωm