Question

a wire of length 10m and 0.02m2 area having a resistivity of 2ohm then the Electrical resistivity of wire 1) 0.004ohm.m. 2) 0.4ohm.m. 3) 40ohm.m 4) 4ohm.m.​

Answer 1

Answer:

The resistivity of the wire is  0.004 ohm meter (option a).

Explanation:

Given: length of wire = 10m, Area= 0.02m² , resistivity= 2Ω

To find: Resistivity of different wires.

Solution:

To find the resistivity of a wire we use the formula:

ρ= R× Area/Length

So,

Resistance (R) = 2ohm

length (l) = 10meter

Area (a) = 0.02m²

The answer in the options is given in Ohm-metre so we do not need to change the units of any values given above.

So, by substituting the values we get,

ρ= 2×0.02/10

ρ=0.04/10

ρ=0.004 ohm meter.

or, Resistivity = 0.004 ohm meter.

The answer comes out to be 0.004 ohm meter.