Q 12-14-111JEE MainJEE Main 2022 (26 Jun, Shift 1)Medium
The I–V characteristics of a p–n junction diode in forward bias are shown in the figure. The ratio of dynamic resistance, corresponding to forward bias voltage of $2\ \text{V}$ and $4\ \text{V}$ respectively, is
Answer: (B) $5 : 1$
Dynamic resistance $r = \dfrac{\Delta V}{\Delta I}$ from the graph:
Near $2\ \text{V}$: $r_1 = \dfrac{2.1 - 2}{(10 - 5)\times10^{-3}} = 20\ \Omega$.
Near $4\ \text{V}$: $r_2 = \dfrac{4.2 - 4}{(250 - 200)\times10^{-3}} = 4\ \Omega$.
$r_1 : r_2 = 20 : 4 = 5 : 1$.
Solution by Sreeraj P, M.Sc Physics