Question

An electric field is applied to a semiconductor. Let the number of charge carries be n and the average drift speed be $\nu$. If the temperature is increased,

• A. both n and $\nu$ will increase
• B. n will increase but $\nu$ will decrease
• C. $\nu$ will increases but n will decrease
• D. both n and $\nu$ will decrease

Answer 1

The correct option is B n will increase but $\nu$ will decrease

When we increase temperature electrons will be excited to conduction band which leads to an increase in number of charge carriers.
An increase in temperature causes atoms to vibrate more, which increases the number of collisions electrons have on their way through the wire and decreases the drift velocity as a whole.