Question

The reverse bias in the junction diode is the changed from $8V$ to $13V$,then the value of current changes from $40\mu A$ to $60\mu A$.The resistance of junction diode will be :

• A. $2\times {10}^5\Omega$
• B. $2.5\times {10}^5\Omega$
• C. $3\times {10}^5\Omega$
• D. $4\times {10}^5\Omega$

Answer 1

The correct option is B $2.5\times {10}^5\Omega$

Resistance of diode $=\frac{\Delta V}{\Delta I}$
$r_d=\frac{(13-8)V}{(60-40)\mu A}$
$=\frac{5}{20}\times {10}^6$
$=\frac{1}{4}\times {10}^6=0.25\times {10}^6$
$=2.5\times {10}^5$ ohm