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Question
When an electric field is applied across a semiconductor ______.
- electrons move from lower energy level to higher energy level in the conduction band.
- electrons move from higher energy level to lower energy level in the conduction band.
- holes in the valence band move from higher energy level to lower energy level.
- holes in the valence band move from lower energy level to higher energy level.
Options
a and b
b and c
d and a
a and c
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Solution
a and c
Explanation:
In the valence band electrons are not capable of gaining energy from the external electric fields. While in the conduction band the electrons can gain energy from the external electric field.
When an electric field is applied across a semiconductor, the electrons in the conduction band (which is partially filled with electrons) get accelerated and acquire energy. They move from lower energy levels to higher energy levels. While the holes in the valence band move from higher energy level to lower energy level, where they will be having more energy.
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