Question

In an intrinsic semiconductor, at any ordinary temperature, the correct relation between the number of electrons per unit volume (\(n_{e}\)) and number of holes per unit volume (\(n_{h}\)) is

• A. \(n_{e}=n_{h}\)
• B. \(n_{e}>n_{h}\)
• C. \(n_{e}\lt n_{h}\)
• D. \(n_{e}=n_{h}=0\)

Hint:

In a pure semiconductor each broken bond creates one electron and one hole.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
An intrinsic semiconductor is a pure semiconductor with no doping.

Step 2: Carrier Generation
At ordinary temperature, thermal energy breaks covalent bonds.
Each broken bond frees one electron and leaves behind one hole.

Step 3: Conclusion
Electrons and holes are created in pairs, so \(n_e = n_h\).
Both are non-zero at ordinary temperature.

Final Answer:
In an intrinsic semiconductor the number of electrons equals the number of holes. \[ \boxed{\text{(A) }n_{e}=n_{h}} \]