Question

determine the resistance of an aluminium tube of length 20cm and of square cross section.the external dimensions of the tube are 5cm and it's thickness is 0.25 cm .resistivity of aluminium is 2.7 ×10^-8 ohmsmeter​

Answer 1

Explanation:

d=10km=10×10

3

meter

d=2.0mm⇒ radius r = 1 mm = 1×10

−3

meter.

⇒ cross sectional area A=πr

2

=π×10

−6

m

2

So resistance R=

A

Pl

=2.7×10

−8

×

π×10

−6

10

4

Ω

⇒R=85.98Ω