At a given temperature, the number of intrinsic charge carriers in a…

At a given temperature, the number of intrinsic charge carriers in a semiconductor is 2.0 x 1010 cm 3. It is doped with pentavalent impurity atoms. As a result, the number of holes in it becomes 8 x 103 cm 3. The number of electrons in the semiconductor is

(A) 2 × 1024 m-3
(B) 4 × 1023 m-3
(C) 1 × 1022 m-3
(D) 5 x 1022 m-3

Ans. The correct answer is therefore:

(C) 1×1022 m−31×1022m−3