Instructions:
(a)4 marks will be allotted for correct question and 1 will be
deducted for incorrect question. (b)More than
one answer can be correct.
Que.
1
A long speciman of p type semiconductor material
A
is +ively charged
B
is electrically neutral
C
has an electric field directed along its length
D
acts as a dipole
Que.
2
Acceptor impurity atoms in Si result in
A
increase forbidden gap
B
reduced forbidden gap
C
new discreate energy level slightly below conduction leval
D
new discreate energy leval slightly above conduction level
Que.
3
in any conductor hall voltage V(H) is proportional to
A
B
B
B^2
C
1/B
D
1/B^2
Que.
4
In BJT with I(infinite)=1 micro.A, a=0.99,the value of I(CEO) is
A
0.01 micro.A
B
0.001 micro.A
C
1 micro.A
D
1000 micro.A
Que.
5
The current gain of a BJT is
A
g(m)*r(o)
B
g(m)/r(o)
C
g(m)*r(pi)
D
g(m)/r(pi)
Que.
6
The velocity of the holes in the n region at X=0
A
12*10^3 cm/sec
B
5*10^3 cm/sec
C
2*10^4 cm/sec
D
none of these
Que.
7
The spectral dencity of pink noise varies as
A
1/f^2
B
f^2
C
1/f
D
f
Que.
8
zener diode is used as a
A
current regulator
B
voltage booster
C
voltage regulator
D
power regulator
Que.
9
three phase half wave rectification,if the input frequency is 50hz then
output frequency is
A
100 hz
B
150hz
C
75hz
D
25hz
Que.
10
For getting low regulated voltages are used
A
zeners
B
SCR
C
transistor
D
chopper
Que.
11
thin film components are formed
A
are made of ceramic
B
are made of silk screening process
C
are formed by photomaskingand diffusion
D
can be made entirely from tantalum
Que.
12
in n-channel FET's are superior to p-channel FEY's because
A
they have lower switching time
B
they have lower pinchoff voltage
C
they have higher input impedance
D
mobility of charge carrier e- in n-channel FET is greater than
the mobility of charge carrier holes in p-channel FET
Que.
13
Which of the following device has the highest input impedance
A
npn transistor
B
JFET
C
UJT
D
MOSFET
Que.
14
the FET
A
has 3 pn-junction
B
use a forward bias junction
C
depands on the variation of a magnetic field for it's operation
D
depands on the variation of a reverse voltage it's operation
Que.
15
transistor in monolithic IC's
A
are made as separate wafer
B
use isolation junction as the collector junction
C
are similar to discrete planner transistor but have the collector
constants on the top surface
D
are identical with discrete planner transistor
Que.
16
encapsulation of a transistor is done to
A
provide mechanical reggedness
B
prevent photo electric effect
C
prevent electrical interference
D
to case heat radition
Que.
17
The most important factor groverning the cost of IC component is
A
the shape of the component
B
area occupied by the component
C
number of electrode connection
D
location of the component on the slice
Que.
18
Extremely low power dissipation and low cost per gate can be achieved
in the following IC
A
ECL
B
CMOS
C
TTL
D
MOS
Que.
19
The following digital IC family can give maximum fan out
A
ECL
B
PMOS
C
CMOS
D
HTL
Que.
20
in SCR the turn off time
A
increases with increases of T
B
is independent of T
C
varies as 1/T
D
varies as 1/T^2
Que.
21
In industrial electronic control
A
AC power system are always used
B
IC's can be used with advantage in feedback control ckt
C
we are simply conceened in establishing stable control with constant
load conditions
D
use of IC's is not of consequence
Que.
22
An IC sence amplifier
A
consists of a linear amplifier a voltage level detector and a
logic pulse forming ckt
B
cannot practically made as a standerad probuct
C
is a memory system
D
consist of four seperate linear amplifier
Que.
23
Forbidden energy gap between valance band and conduction band is least
in the case of
A
mica
B
pure Si
C
pure Ge
D
impure Si
Que.
24
At 0degreeK Forbidden energy gap in Si is
A
.785 eV
B
1.21 eV
C
.72 eV
D
1.1 eV
Que.
25
acceptor impurity atoms in a result in new
A
wide energy band
B
narrow energy band
C
discrete energy leval just below conduction leval
D
discrete energy leval just above conduction leval
Que.
26
relative dielectric constant of Si is
A
12
B
14
C
16
D
20
Que.
27
Diffusion constant for free e- in Ge expressed in (cm^2/sec) is
A
13
B
40
C
34
D
99
Que.
28
when Ge is doped with penta valent impurity,the resulting material is
A
p-type semiconductor
B
n-type semiconductor
C
intrisic semiconductor
D
no longer semiconductor
Que.
29
microwave IC's
A
have inferior performance
B
are not possible to fabricate
C
always use discreate components
D
are initally being made as hybrid type on ceramic substrates
Que.
30
cost of monolithic IC is
A
independent of the quantity produced
B
roughly proportional to the area of ckt wafer
C
proportional to the number of ckt elements
D
increases with increase of quantity produced
Que.
31
The main advantage of TRAPATT diode over IMPATT diode is it's
A
higher output
B
higher efficiency
C
lower noise
D
capability to operate at higher freq.
Que.
32
in an unbiased pn junction the junction current is equilibrum is
A
due to diffusion of majority carriers
B
due to diffusion of minority carriers
C
zero due to equal and opposite currents crossing the junction
D
zero because no charges cross the junction
Que.
33
In Ge diode the cutin voltage is about
A
0.2v
B
0.6v
C
1.1v
D
2v
Que.
34
In a pnp transistor operating in the active region the concentration of
minority carriers holes in the n region at collector junction
J(e) is
A
zero
B
thermal equilibrium value p(no) of emittor
C
thermal equilibrium concentration of holes in collector region
D
same as at J(e)
Que.
35
In the uniformly doped abrupt p-n junction, the doping level of the n-side
is four times the dopinglevel of the p-side. the ratio of the deplation
layer widths is
A
0.25
B
0.5
C
1.0
D
2.0
Que.
36
An n-channel JFET has a pinch off voltage of Vp=-5v,Vds(max)=20v and
(delta)(m)=2mA/V.The minimum 'ON' resistance is achieved
in the JFET for
A
V(gs)=-7v, V(ds)=0v
B
V(gs)=7v, V(ds)=0v
C
V(gs)=0v, V(ds)=20v
D
V(gs)=-7v, V(ds)=20v
Que.
37
The reverse saturation current of a solar cell is 10 and the light generated
short ckt current is I for 1 sun illuminated. the open ckt voltage of
the solar cell under one sun illumination is
A
KT/q ln(1+I(L)/I(O))
B
q/KT ln(1+I(L)/I(O))
C
KT ln(I(O)+I(L))
D
KT ln(I(L)-I(O))
Que.
38
The need of centre tap is eliminited in full wave_______ rectifier
A
vacuum tube
B
semiconductor
C
crystal diode
D
bridge
Que.
39
When a lossy capzcitance with a dielectric of permittivity e and conducitivity
o- operates at a freq. w, the loss tangent for the capacitor is given by
A
wo-/e
B
we/o-
C
o-/we
D
o-we
Que.
40
Micro-program is
A
The name of the source program in microcomputer
B
the set of instructions indicating the primitive operations in
a system
C
the general name of a MACRO'S in assembly language programming
