Question

As shown in the diagram we get some value of voltage V${}_o$. Now the direction of Ge diode becomes reverse, then we get some other value of voltage V${}_0$.Find the difference of voltage V${}_0$, in both the cases.

• A. 0. 3 V
• B. 0 . 4 V
• C. 0 . 7 V
• D. 1 . 0 V

Answer 1

Answer: (B)

0 . 4 V

Germanium and silicon semi-conductors starts conducting at 0.3 V and 0.7 V respectively

Initially, when the connection is made as shown in the figure, only germanium will be conducting the current because of low voltage

The value $V_0$ will be

$V_0=V-V_{Ge}=12-0.3=11.7\text{V}$

When the Germanium diode connection is reversed, it will not conduct the current and now silicon will conduct current

The value $V_0$ will be

$V_0=V-V_{Si}=12-0.7=11.3\text{V}$

The difference of voltage $V_0$ in both cases = 11.7 – 11.3 = 0.4 V

Therefore, Option (B) is the right answer