What's the reason that In an unbiased n-p junction , electrons diffuse from n-region to p-region :

Options

A. a) holes in p-region attract them
B. b) Electrons travel across the junction due to potential difference
C. c) Only electrons move from n to p region and not the vice-versa
D. d) electron concentration in n-region is more compared to that in p-region

Answer

A, D

Explanation

`dF` on each of the two symmetric elements
`=1xx((2dy)/(sqrt(3)))B_(0)yxx(sqrt(3))/2`
`impliestau=int_(0)^((sqrt(3)a)/2)(2B_(0)l_(y)dy)/(sqrt(3))xx((sqrt(3))/2a-y)`
`=2/(sqrt(3))IB_(0) int^((sqrt(3))/2 a) ((sqrt(3))/2a-y)ydy=(IB_(0)a^(3))/8`
`tau_(friction)=2{(mumg)/a int_(0)^(a//2) xdx}=(mumga)/4`
For the frame to rotate
`(IB_(0)a^(3))/8le(mumga)/4`
`B_(0)le(2mumg)/(Ia^(2))`