An n type semiconductor is illuminated by a steady flux of photons with energy greater than the band gap energy. The change in conductivity Δσ obeys which relation? [ Here, e is the electron charge, μn electron mobility, μp hole mobility, Δn (Δp) is the excess electron (hole) density ].

An n type semiconductor is illuminated by a steady flux of photons wit

1.	An n type semiconductor is illuminated by a steady flux of photons with energy greater than the band gap energy. The change in conductivity Δσ obeys which relation? [ Here, e is the electron charge, μn electron mobility, μp hole mobility, Δn (Δp) is the excess electron (hole) density ].
A.	Δσ = 0
B.	Δσ = e(σn + σp) Δn
C.	Δσ = e(μnΔn - μpΔp)
D.	Δσ = e μnΔn
Answer» C. Δσ = e(μnΔn - μpΔp)