Quiz on Semiconductor Physics

Q.1 The majority carriers in n-type semiconductors are

electrons in conduction band
holes in valence band
both (a) and (b)
none of these

Q.2 By doping fifth group elements in germanium crystal, which type of semiconductor material is obtained

positive
negative
neutral
none of these

Q.3 In an n-type semiconductor the Fermi-level lies

above the top of the valence band
below the bottom of the conduction band
In the middle of the forbidden gap
near the conduction band

Q.4 On increase of temperature, the Fermi level shifts upwards in

p-type semiconductor
n-type semiconductor
intrinsic semiconductor
none of these

Q.5 The value of Fermi-distribution function at absolute zero (T = 0 K) is 1, i.e., F(E)=1, under the condition

Ef>E
E>Ef
E=Ef
E>>Ef

Q.6 At any temperature T and for E = EF, the Fermi-distribution function becomes

0
1
2
0.5

Q.7 What is the direction of current flow in a forward-biased pn junction diode?

From n-type to p-type
From p-type to n-type
No current flow
None of the above

Q.8 What is the direction of current flow in a reverse-biased pn junction diode?

From n-type to p-type
From p-type to n-type
No current flow
None of the above

Q.9 Which type of semiconductor material has negative Hall coefficient

p-type
n-type
intrinsic
none of these

Q.10 The semiconductor material NOT used in LED is

Silicon carbide
GaAsP
GaAs
Si