Question

if the resistance of a wire length 1.20 m and dimeter 0.4 mm is found to be 2.5 ohm, what is the specific resistance of the material of the wire? ​

Answer 1

Answer:

vjwpgwlkdwpgggf ffojcpjqjscdigxwejpgwidedip

Answer 2

Correct Answer :- 26.17*1/10⁸ Ωm

Step by step explanation :-

Here , R = ρ L/A. ( ρ = specific resistance )

R = 2.5Ω

L = 1•2 m

Now ,

A = πr² = π ( D / 2 )²

D = 0.4 mm = 0.4 / 1000 m = 4*1/10⁴

A = π ( 2*1/10⁴)² = 4π * 1/10⁸ m²

Also,

2.5 = ρ * 1.2 / 4π * 1/10⁸

ρ = 10π * 1/10⁸ /1.2

( we know that , π = 3.14 )

Therefore , ρ = 10 * 3.14 * 1/10⁸ /1.2

Hence , ρ = 26.17 *1/10⁸Ωm