Question

Q4. The specific resistance of a wire


​

Answer 1

Answer:

The resistance of a wire is directly proportional to the specific resistance of the material

Explanation:

The resistance of a wire is directly proportional to the specific resistance of the material

Answer 2

Answer:

The specific resistance/resistivity of a wire is specific to a certain elements

Explanation:

We know that,

Resistance is directly proportional to length, inversely proportional to Area of Cross section,

R ∝L

R ∝(1/A)

Thus,

R ∝L/A

Thus, to change the Proportionality symbol, we must add a constant, ρ (rho)

Thus,

R = ρL/A

Now, ρ is also called as the resistivity or specific resistance of that material.

Each material has it's own resistivity. The specific resistance or resistivity of a wire is the property of the material only. It does not depend on mass, length or cross-section of wire. It may change with temperature. 

So, resistivity is specific to an element, which means different elements have different resistivity,

Silver has the least resistivity

= 1.59 × 10^(-8)

Nichrome has the highest resistivity

= 100 × 10^(-8)

We look into resistivity to find out the Heat generated when electric current is passed through the wires, thus, higher the resistivity higher the heat generated.

Thus,

The specific resistance/resistivity of a wire is specific to a certain elements

Hope it helped and you understood it........All the best