In an unbiased p - n junction electrons diffuse from n-region to p-region because:

In an unbiased p - n junction electrons diffuse from n-region to p-region because:
  1. electrons travel across the junction due to potential difference
  2. only electrons move from n to p region and not the vice - versa
  3. electron concentration in n - region is more as compared to that in p - region
  4. holes in p - region attract them

Solution

In a p-n junction diffusion occurs due to spontaneous movement of majority charge carrier from the region of high concentration to low concentration.

Asked in: JEE Main 2015 (10 Apr Online)

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