Question

ten identical lengths of wire are laid closely side-by-side. their combined width is measured and found to be 14.2mm. calculate:
a. the radius of a single wire.
b. the volume in mm³ of a single wire if its length is 10.0cm.

content quality answer needed!

Answer 1

a) The combined width is the sum of the diameters of the ten rods.

The diameter of one rod is thus :

14. 2/10 = 1.42 mm

b) The volume of a single wire.

We first change the length to be in mm as follows.

1 cm = 10mm

10 × 10 = 100 mm

Volume = πr²h

r = 1.42 / 2 = 0.71

Volume = 3.142 × 0.71² × 100 = 158.39

= 158.39 mm³

Answer 2

Answer:

The resistance of the original single wire of copper =R

1

=

πr

1

2

ρl

, where r

1

=6mm and R

1

=10Ω

The resistance of each new copper wire =R

2

= πr2

2ρρ , where r 2

=2mm

∴ R 1 R 2

=( r2r r1 ) 2

=( 26 ) 2= 19

i.e., R

2 =9R

1 =90Ω