Question

Assertion (A): We cannot form a p-n junction diode by taking a slab of a p-type semiconductor and physically joining it to another slab of an n-type semiconductor. Reason (R): In a p-type semiconductor, \( n_e \gg n_h \) while in an n-type semiconductor \( n_h \gg n_e \).

• A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false and Reason (R) is also false.

Hint:

A p-n junction diode can be formed by joining p-type and n-type semiconductors. The electron and hole concentrations in each type of semiconductor are different.

Answer 1

The Correct Option is D

The assertion is false because a p-n junction diode can indeed be formed by joining a p-type semiconductor with an n-type semiconductor. This forms a p-n junction where the free electrons from the n-type material combine with holes in the p-type material to form the depletion region.
The reason is true because in a p-type semiconductor, the number of electrons \( n_e \) is small and the number of holes \( n_h \) is large. In an n-type semiconductor, the number of electrons \( n_e \) is large, while the number of holes \( n_h \) is small. Thus, the assertion is false and the reason is true.