Question

A rectangular conductor with a cross sectional area of 1.04 square millimeters (mm) ^2 has a resistance of 0.075 ohms. What would be its resistance, if it's cross sectional area were 2.08mm^2​

Answer 1

Answer:

0.0375 ohms

Explanation:

The resistance of a material is the product of the resistivity of the material by the length of the material divided by its cross-section area.

Mathematically,

resistance= resistivity × length/area

In this case the resistivity of the material is the same, and the length is the same thus, assume a length of 1 unit, the cross-section area is the one changing

In applying the formula,

resistivity is r and length is l=1 unit, find the resistivity the material as;

resistance= resistivity * length /area

0.075=r*1/1.04

0.075=r*0.9615

0.075/0.9615 =r

r=0.078

use the r=0.078 , a length of 1 unit (assumed), and area of 2.08 mm² to find the new resistance

Resistance= resistivity * length /area

Resistance = 0.078*1/2.08

Resistance= 0.078 * 0.4807 = 0.0375 ohms

Point to note here is that the greater the cross-section area, the less the resistance.