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Assertion :-(A) semiconductors are so...

Assertion :-(A) semiconductors are solids with conductivites in the intermediate range from`10^(-6)-10^(4) ohm ^(-1)m^(-1)`
Reason :-(R ) internmediate conductivity in semiconductor Is due to partially filled valence band .

A

If both assertion and reason are true and reason is the correct explanation of assertion

B

If both assertion and reason are true but reason is not the correct explanation of assertion.

C

If assertion is true but reason is false

D

If both assertion and reason are false

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze both the assertion and the reason provided. ### Step 1: Understanding the Assertion The assertion states that "semiconductors are solids with conductivities in the intermediate range from \(10^{-6}\) to \(10^{4}\) ohm\(^{-1}\)m\(^{-1}\)". - **Explanation**: This is indeed true. Semiconductors have conductivities that fall between those of conductors (metals) and insulators. The typical conductivity range for semiconductors is approximately \(10^{-6}\) to \(10^{4}\) ohm\(^{-1}\)m\(^{-1}\). ### Step 2: Understanding the Reason The reason states that "intermediate conductivity in semiconductors is due to a partially filled valence band". - **Explanation**: This statement is misleading. While it is true that semiconductors have a valence band and a conduction band, the intermediate conductivity is primarily due to the small energy gap between the valence band and the conduction band, which allows electrons to jump from the valence band to the conduction band. The valence band itself is typically filled, and it is the conduction band that is partially filled when electrons are excited. ### Step 3: Conclusion - The assertion is **true** because it accurately describes the conductivity range of semiconductors. - The reason is **false** because the intermediate conductivity is not solely due to a partially filled valence band, but rather due to the small energy gap between the valence band and conduction band. ### Final Answer - Assertion (A) is true. - Reason (R) is false. Thus, the correct option is that the assertion is true, but the reason is false. ---
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