Modern Physics Ques 221
- At $0.3 $ $V$ and $0.7$ $ V$, the diodes $Ge$ and $Si$ become conductor respectively. In given figure, if ends of diode $Ge$ overturned, the change in potential $V _0$ will be
(Main 2019, 9 Jan II)
(a) $0.2 $ $V$
(b) $0.6 $ $V$
(c) $0.4 $ $V$
(d) $0.8 $ $V$
Show Answer
Answer:
Correct Answer: 221.(c)
Solution:
- Initially $Ge$ and $Si$ are both forward biased. So, current will effectively pass through $Ge$ diode with a voltage drop of $0.3$ $ V$.
$\therefore$ Initial output voltage, $V _0=12-0.3=11.7 $ $V$
If $Ge$ is reversed biased, then only $Si$ diode will work.
In this condition, output voltage
$ V _0=12-0.7=11.3 $ $V $
$\therefore$ Change in output voltage $=11.7-11.3=0.4 $ $V$
BETA
