Question

the resistance of a wire 0.01 cm radius is 10 ohms if the resistivity of the material of the wire is 50*10 power 8 ohms m find the length of the wire

Answer 1

Answer:

resistance of wire , R = 10 ohm

radius of base of wire , r = 0.01cm = 0.01/100 m

r = 1 × 10^-4 m

base area , A = πr² = 3.14 × (10^-4)² = 3.14 × 10^-8 m²

resistivity of the material of wire , ρ = 50 × 10^-8 ohm.meter

we know, formula

R = ρL/A

L = RA/ρ

= 10 ohm × 3.14× 10^-8m²/50 × 10^-8 ohm.meter

= 31.4/50 m

= 0.628 m

hence, length of wire is 0.628 m