Q1. The forbidden energy band gaps in conductors, semiconductors and insulators are \(EG_{1},\)\(EG_{2}\) and \(EG_{3}\) respectively. The relation among them is:
\(EG_{1}=EG_{2}=EG_{3}\)
\(EG_{1}<EG_{2}<EG_{3}\)
\(EG_{1}>EG_{2}>EG_{3}\)
\(EG_{1}<EG_{2}>EG_{3}\)
Explanation:
Hint: Recall Band’s theory of solids.
Step: Find the correct relation between forbidden energies.
The forbidden gap in the conduction, semiconductor, and insulator is shown in the figure below;
Therefore, the correct relation between them is \({EG}_{3}>{EG}_{2}>{EG}_{1}\).
Hence, option (2) is the correct answer.
Q2. Under what conditions will diode \(D_1\) conduct?
\(V_A>V_B+V_0\)
\(V_A<V_B+V_0\)
\(V_A>V_B-V_0\)
\(V_A<V_B-V_0\)
Explanation:
Hint: In the forward bias diode \(D_1\) will conduct.
Step: Find the conditions in which the diode \(D_1\) will conduct.
For the diode to conduct or forward forward-biased, the voltage \((V_B+V_0)\) must exceed the voltage \((V_A).\)Therefore, the diode is forward-biased if \(V_A<V_B+V_0\).
Hence, option (2) is the correct answer.
