Question

Ge & si diodes conduct at 0.3v and 0.7v respectively in the following figure. If Ge diode connections are reversed the value of Vo changes by 1 0.2v 2) 0.4v 3) 0.6v 4) 0.8v ​

Answer 1

If Ge diode connections are reversed the the value of V₀ changes by 0.4 Volt.

Given-

• Ge diode conducts at 0.3 Volt

• Si diode conducts at 0.7 volt

Without reversing the connection initial value of V₀ is

We can clearly see from the attached figure that positive terminal of the battery is connected with the positive part of diode, So diode is forward bias.

Current will prefer less voltage diode i.e. Ge diode which is having 0.3 Volt

We know that-

V₀ = IR

By substituting the value we get

V₀ = 12-0.3/5 × 5 = 11.7 Volt

When diode connections are reversed then, Ge diode will not conduct current because Ge diode changes into reverse bias.

So current will conducted only by Si diode. Now

V₀ = IR

V₀ = 12 - 0.7/5 × 5 = 11.3 volt

Change in V₀ (ΔV₀) = 11.7 - 11.3 = 0.4 Volt