Question

the resistivity of iron is 1*10-7 ohm-m.the resistance of a iron wire of particular length and thickness is 1 ohm.if the length and the diameter of wire both are doubled,then the resistivity in ohm-m will be (explain)
a)1*10-7
b)2*10-7
c)4*10-7
d)8*10-7

Answer 1

a) 1*10^7

This is because the resistivity of a substance never changes. It is a constant value for one substance.

Answer 2

The answer is (a) 1 * 10^(-7) ohm m

A conductor's inherent ability to obstruct the flow of electricity is known as resistivity. Each material's resistance is distinct. Even when a material's shape or dimensions are changed, its resistance does not change. However, by changing the material's temperature conditions, resistivity can be modified.

We have been given that the the resistivity of iron is 1*10-7 ohm m. Also, the length and diameter of the wire are doubled. This might alter the resistance. However, these changes cannot alter the resistivity. Thus the resistivity of iron continues to be 1 * 10^(-7) ohm m

#SPJ3