A semicoductor is known to have an electron concentration of 8 x 101 per cm and a hole concentration of 5 x 1012 per cm What is the resistivity of the sample if the electron mobility is 23,000 cm? /Vs and hole mobility is 100 cm2/ Vs? (A) 3.4Q cm (C) 0.5 n cm (B 2.5 cm (D) none of these
Answer would be (A) 3.4 Ohm cm
As Resistivity depends on the no. of electrons present
For conductivity we have formula
∆ = mobility of electrons × concentration of electrons ...