Question

On heating a conductor, its resistance.

Answer 1

Hint: In order to solve this question, we are going to first explain what the scenario is in the interior of a conductor whenever the temperature is increased. Then, resistance is explained and based on what the formula is for the resistance, we can tell the effect of heating of conductor on resistance.

Formula used:
The formula of the resistance of conductor is given by
$$R=\rho {\displaystyle \frac{L}{A}}$$
Where$$\rho$$, $$L$$and $$A$$are the resistivity, length and area of the conductor respectively.

Complete step-by-step solution:
When a conductor is heated, there is more movement of the free ions and electrons, which increases the number of collisions between them .This prevents more and more current from flowing through the conductor. This increases the resistance of the conductor also.
Now, resistance is the property of a conductor to oppose the flow of current. As electrons move through a metal conductor, some collide with atoms, other electrons or impurities. These collisions cause resistance and generate heat. Heating the conductor even more causes more and more collisions of the ions on their way to freely flow and make the current pass through the conductor. Thus, heating causes the resistance to increase even more.

Note: Alternatively, The formula of the resistance is given by
$$R=\rho {\displaystyle \frac{L}{A}}$$
Where$$\rho$$, $$L$$and $$A$$are the resistivity, length and area of the conductor respectively. Now the resistivity of the conductor is directly proportional to the temperature. Hence, on increasing the temperature, resistivity and hence resistance also increases.