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. The mobility of electrons in a semiconductor is defined as the
A) Drift velocity per unit magnetic field

B) Diffusion velocity per unit magnetic field

C) Drift velocity per unit electric field

D) Diffusion velocity per unit electric field

. In an intrinsic semiconductor, the free electron concentration depends on
A) The width of the forbidden energy band of the semiconductor

B) Effective mass of the electrons only

C) Effective mass of the holes only

D) Temperature of the semiconductor

. Silicon is not suitable for fabrication of LEDs, because it is
A) Adirect band gap semiconductor
B) An indirect band gap semiconductor
C) A narrow band gap semiconductor
D) A wide band gap semiconductor

. Resistivity of a semiconductor depends on
A) Carrier mobility
B) Life time of polycrystalline materials

C) Carrier concentration in intrinsic semiconductor
)

D) Carrier concentration in extrinsic semiconductor

. The diffusion length of a carrier depends on
A) The shape of the semiconductor
B)
C) The mobility and lifetime of the carriers
D) The mobility of the carriers alone

The life time of the carriers alone

. In an n-type semiconductor, as temperature increases, the Fermi level
A) Moves towards the conduction band

B) Moves towards middle of forbidden energy gap

C) Does not shift

D) May or may not shift depending on the concentration of donor atoms