Question

The $\text{I - V}$ characteristics of a $\text{p-n}$ junction diode in forward bias is shown in the figure. The ratio of the dynamic resistance, corresponding to forward biast voltage of $2V\text{and}4V$ respectively, is

• A. $1:2$
• B. $1:40$
• C. $20:1$
• D. $5:1$

Answer 1

The correct option is D $5:1$

Dynamic resistance $=\frac{dV}{dI}$

$\Rightarrow r_1=\frac{2.1-2}{10-5}k\Omega$

and $r_2=\frac{4.2-4}{250-200}k\Omega$

$\Rightarrow r_1:r_2=5:1$