Question

Define temperature coefficient of resistance.

Answer 1

Hint: For defining the term temperature coefficient of resistance, we will mention all variations of resistance with the change in temperature, and temperature coefficient. We will also include the formula of it in order to explain it better. Few examples of substances with their coefficient value can also be the part of definition.
Formula used:
${{R}_{T}}={{R}_{\text{o}}}\left( 1+\alpha \left( \Delta T \right) \right)$ where T is temperature, ${{R}_{T}}$ and ${{R}_{\text{o}}}$ are variations in resistance and $\alpha $ is temperature coefficient of resistance.

Complete answer:
Temperature coefficient resistance: If we are getting variations in resistance with the action of change in temperature in degrees then we call that measurement as a temperature coefficient resistance. We measure it with the help of formula ${{R}_{T}}={{R}_{\text{o}}}\left( 1+\alpha \left( \Delta T \right) \right)$.

There are two types of temperature coefficients and their names are positive temperature coefficient, negative temperature.

By the positive temperature resistance, we mean the increment in the resistivity and resistance of any substance which is proportional to the decrease in relaxation time of collisions.
On the other hand, the negative temperature coefficient, there is an increase in the number of carriers of charge per unit of volume which increases with the increase in temperature.

Additional Information:
The temperature coefficient of Platinum is 0.003927, Tin is 0.0042, Gold is 0.0034, Silver is 0.0038 and Iron is 0.00651. Moreover, the same value for Copper is 0.00386, Aluminum is 0.00429 and Tungsten is 0.0045.

Note:
Whenever we get differences between resistances only by changing temperature then in that case we will always apply the definition of temperature coefficient resistance. The variation in resistance depends upon Resistance, Temperature and Temperature coefficient resistance $\alpha $. There are many materials whose value related to this coefficient is fixed. But if value of change in temperature is given to us along with the value of change in resistances then we will apply the formula ${{R}_{T}}={{R}_{\text{o}}}\left( 1+\alpha \left( \Delta T \right) \right)$ and solve further.