Question

A resistor connected to a battery is heated due to current through it. Which of the following quantity does not vary?

• A. resistance
• B. drift velocity
• C. resistivity
• D. number of free electrons

Answer 1

The correct option is D number of free electrons

Resistance, resistivity and drift velocity varies with relaxation time which is dependent on temperature.
Number of free electrons in a conductor remains invariant even if its temperature changes.