Question

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

• A. both $n$ and $v$ will increase
• B. $n$ will increase and $v$ will decrease
• C. both $n$ and $v$ will decrease
• D. $n$ will decrease and $v$ will increase

Answer 1

Answer: (B)

As the temperature is increased, more electrons are able to move from valance band to conduction band, hence the number of charge carriers increases but with increase in the temperature the frequency of collisions increases so the average drift speed decreases