3

Maximum : 100 marks

Time: | hour and 15 minutes ,

The distribution of electrons in the conduction band is given by :
(A) (density of quantum states ) x (energy of a state)
(B) (density of quantum states) x (probability a state is occupied)
(C) (energy of quantum states) x (probability a state is occupied)
(D) (energy of quantum states) x (chemical potential of a state)

Temperature coefficient of diode at room temperature is
(A) -1.22mVPC (8) -1.48 ೧1೫0 0
(0) -1.68 ۷۴ ۲ (D) -1.82 7४/०८

When the reverse bias increases for a diode, the PN junction capacitance :
(ಗಿ) Increases, exhibiting inverse square relation
(B) Decreases, exhibiting inverse square relation
(C) Decreases, exhibiting inverse square root relation
(D) Increases, exhibiting inverse square root relation

Consider an ideal intrinsic semiconductor in thermal equilibrium. No external forces or fields
are applied to this semiconductor. At temperatures above 0 K, the electron concentration in
the conduction band is non-zero because :

(4) some electrons from dopant atoms will overcome the bandgap by gained thermal
energy

(B) some electrons from the conduction band will overcome the bandgap by gained
thermal energy

(C) some electrons from dopant atoms will overcome the ionization energy by gained
thermal energy

(D) some electrons from the valence band will overcome the bandgap by gained
thermal energy . ⋅

⋀⊐∐⋂≏↴≖∘∥⋮⊲⊡⋅↕↿⊾⊞⊧↿↧⊟⋮∘∐≀⋯∣⋯⊠⊑⊐⊟⇂∙⇇⋯≘↻⊟≖≡↧∎≖⋮⋥−⊵∅∣≔∆∃⊐⋯≏≖↿∘∦∎∇∘∥∙⊠⊰⊵≡∇↗∥⊐↔⊑∄≖↡≡
source cut off voltage is :

fA) -5V (B) 51%
(0) ൧൭൦ (D) -10V

The capacitance in parallel with forward biased base emitter terminals of a transistor is
known as :

(A) Depletion Capacitance (B) Drift Capacitance
(C) Diffusion Capacitance (D) Doping Capacitance

[P.T.0.]