Question

True or False: Most conducting materials have different resistances at different temperatures.

 

Answer 1

Concept and reason

The required concept to solve these questions is temperature effects on resistance.

Use the concepts of the temperature and atomic structure to find most conducting materials have different resistances at different temperatures is true or false.

Fundamentals

The flow of current is nothing but the movement of electrons from one atom to another, under the electric field's influence.

Electrons are negatively charged particles repelled by a negative electric charge and attracted by a positive electric charge.

The electric potential applied across the positive and negative end of a conductor electrons will migrate from atom to atom towards the positive terminal.

However, some of the electrons are free to migrate, and another atom would hold tightly to their particular atom that the applied electric field cannot dislocate them.

The current flow through the material is due to free electrons' movement, and then the material is said to be a conductor.

 

The expression for the resistor temperature dependence is,

$$ R=R_{0}\left[1+\alpha\left(T-T_{0}\right)\right] $$

Here, R is the resistance, \(R_{0}\) is the initial resistance,\(\alpha\) is the temperature coefficient, \(T\) is the final temperature, and \(T_{0}\)​ is the initial temperature.

The valence electrons in the conductor are free to move throughout the lattice.

The electrons move randomly until an external electric field is applied. Then the electric field forces the electron to move in the opposite direction to the field.

Then the electron still moves randomly but with a superimposed and produces current.

As the temperature increase, the positive ions vibrate more and more collision occurs between the valence electrons and the vibrating ions.

That drift motion of the electron reduces the current.

Hence, most conducting material has different resistance at different temperature.

The above statement is, True.

Ans:

Most conducting material has different resistance at different temperature is, True.