Question

A wire of a material is 15cm long and has a cross section of 0.5cm2.If the resistance along the length is 15 ohms, what will be it's resistivity

Answer 1

R=p×L/A
p= R×A/L
L= 15cm=15/100 m
A= 0.5cm2 = 0.5/10000m2
R= 15ohm
$p = 15 \times \frac{5}{100000} \times \frac{100}{15}$
$p = \frac{5}{1000}$
$p = 5 \times {10}^{ - 3}$