1. A silicon sample is uniformly doped with 1016
phosphorous
atoms / cm3 and
2x 1016 boron atoms/cm3 . if all the dopants are
fully
ionized, the material is
(a) n-type
with carrier concentration of 1016 /cm3
(b) p-type
with carrier concentration of 1016 /cm3
(c) p-type
with carrier concentration of 2x 1016 /cm3
(d) n-type with carrier concentration
of 2x1016 /cm3
2. An n-type silicon sample, having electron mobility µn
twice
the hole mobility µp, is subjected to a steady illumination such
that the electron concentration doubles from its thermal
equilibrium value. As
a result, the conductivity of the sample
increases by a factor of……….
Ans : 2
Ans : 2
3. The small signal capacitance of an abrupt P+N
junction is
1 nF/cm2 at zero bias. If the built in voltage is 1
volt, the
capacitance at a reverse bias voltage of 99 volts is equal to …..
Ans : 0.1 nF /Cm2
Ans : 0.1 nF /Cm2
4. Referring to the figure, the switch S is in position 1 initially and
steady state conditions exist from time t=0 to t = t0. The switch
is suddenly thrown into position 2. The current I flowing through
the 10K resistor as function of time from t=0, is …………
(Give the sketch showing the magnitudes of the current at t=0,
t=t0 and t=∞)
5. Discrete transistors T1 and T2 having maximum collector
current rating of 0.75 Amps are connected in parallel as shown
in the figure.
This combination is treated as a single transistor to
carry a total current of
1 Amp, when biased with self bias
circuit. When the circuit is switched on, T1
draws 0.55 Amps
and T2 draws 0.45 Amps. If the supply is kept on continuously,
ultimately it is very likely that
(a) Both T1
and T2 get damaged
(b) Both T1
and T2 will be safe
(c) T1 will
get damaged and T2 will be safe
(d) T2 will
get damaged and T1 will be safe
6. The built in potential of the gate junction of an-channel
JFET
is 0.5 volts. The drain current saturates at VDS = 4.0 volts
when VGS = 0. The pinch off voltage is ______________
Ans : - 4 volts
Ans : - 4 volts
7. In figure, all transistors are identical and have a high
value of
beta (β). The voltage VDC is equal to _____
Ans : 5 volts
8. In figure the input Vi is a 100 Hz triangular
wave having a
peak to peak amplitude of 2 volts and an average value of
zero
volts. Given that the diode is ideal, the average value
of the output Vo
is ______ Ans : 0.3 Volts
9. In figure, the n-channel MOSFETs are identical and their
current
voltage characteristics are given by the following expressions:
Ans : 1 mA
Where are the solutions for remaining answers. Can you please mail me the answer key. Thank you
ReplyDeletecan you mail me the remaining answers
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