Question:

Ge and Si diodes start conducting at 0.3 V and 0.7 V respectively. In the following figure if Ge diode connection are reversed, the value of Vo changes by : (assume that the Ge diode has large breakdown voltage)

0.2 V

0.6 v

0.8 V

0.4 V

For shown case
Vo = 12 - 0.3 = 11.7
In the second case
Vo = 12 - 0.7 = 11.3
So difference = 11.7 - 11.3 = 0.4V is observed.