Question

what will be the resistivity of a metal wire of 3 m length and 0.4mm in diameter if the resistance of the wire is 55 electric bulb​

Answer 1

Answer:

The resistivity of the metal is \rho = 4.239\times10^{-6}\ \text{\O}mega mρ=4.239×10

−6

Ømegam .

Explanation:

Given that,

length of wire l = 2 m

Resistance R = 30 ohm

diameter d =0.6 mm

Radius = 0.3 mm

We know that,

The resistivity of the metal is

R = \dfrac{\rho l}{A}R=

A

ρl

\rho = \dfrac{RA}{l}ρ=

l

RA

....(I)

Put the value of R,l and A in equation (I)

\rho = \dfrac{30\times3.14\times3\times3\times10^{-8}}{2}ρ=

2

30×3.14×3×3×10

−8

\rho= 423.9\times10^{-8}\ \text{\O}mega mρ=423.9×10

−8

Ømegam

\rho = 4.239\times10^{-6}\ \text{\O}mega mρ=4.239×10

−6

Ømegam

Hence, The resistivity of the metal is \rho = 4.239\times10^{-6}\ \text{\O}mega mρ=4.239×10

−6

Ømegam