Question

Assertion : The energy gap between the valence band and conduction band is greater in silicon than in germanium. 

Reason : Thermal energy produces fewer minority carriers in silicon than in germanium.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

The correct option is (a) Both A and R are true and R is the correct explanation of A.

Explanation:

Mathematically, the number of e-h pairs in the intrinsic semiconductor is given by

Now since in silicon the number of e-h pairs is less than that in germanium, the energy gap E_g in silicon is more than that in Ge.