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Question
An electric field is applied to a semiconductor. Let the number of charge carries be nand the average drift speed by v. If the temperature is increased,
Options
both n and v will increase
n will increase but v will decrease
v will increase but n will decrease
both n and v will decrease.
Solution
n will increase but v will decrease
As we increase the temperature, additional electron‒hole pairs are created in a semiconductor. As a result, the number of charge carriers increases.
Now, drift velocity ( vd) is given by
`vd =(-eEr)/m`
As the temperature increases, the relaxation time of charge carriers (T) decreases. As a result, vd decreases.
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