In diffusion process . . . . . . . . . impurity is desired. A. n type B. p type C. np type D. None of the mentioned

The correct answer is: A. n type

In diffusion process, n type impurity is desired. This is because n type impurity atoms have more electrons than the semiconductor material they are added to. This creates an excess of negative charge carriers in the semiconductor, which makes it a better conductor of electricity.

P type impurity atoms have fewer electrons than the semiconductor material they are added to. This creates an excess of positive charge carriers in the semiconductor, which makes it a poorer conductor of electricity.

Np type impurity is not a valid option.

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