Q 12-14-201JEE MainJEE Main 2017 (8 Apr)Easy
The $V$–$I$ characteristic of a diode is shown in the figure. The ratio of forward to reverse bias resistance is:
Answer: (C) $10^{-6}$
Forward bias (linear region from $0.7$ V to $0.8$ V):
$$R_f = \frac{\Delta V}{\Delta I} = \frac{0.8 - 0.7}{(20 - 10)\times10^{-3}} = 10\ \Omega$$
Reverse bias: $R_r = \dfrac{10\ \text{V}}{1\ \mu\text{A}} = 10^7\ \Omega$.
$$\frac{R_f}{R_r} = \frac{10}{10^7} = 10^{-6}$$
Solution by Sreeraj P, M.Sc Physics