Question

PLEASE ANSWER THIS URGENT!!!! Find the resistance of an aluminum wire of length 400m and cross section 2 mm2 (Given specific resistance of aluminium is 2.75×10^-8 ohm metre)

Answer 1

ans will be 5.5 ohm

solution:
using formula,
R = p ×l/A
here : R= resistance = ?
p = resistivity =
$2.75 \times {10}^{ - 8} ohm \: metre$

l = length = 400m
A = area of cross section =
$2 {mm}^{2} = 2 \times {10}^{ - 6} {m}^{2}$
putting the values in the formula:
$resistance = 2.75 \times {10}^{ - 8} \times 400 \div 2 \times {10}^{ - 6} = 5.5$