Prasar bharati online mock exam(technical) question paper
1.
Which of
the following is the ideal characteristics of OP-AMP
A.
Bandwidth is zero
B.
Offset voltage is infinite
C.
Output voltage is infinite
D.
CMMR
is infinite
2.
A signal has frequency components from 300Hz to
2 kHZ. The minimum possible rate at which the signal has to be sampled
A.
600Hz
B.
900Hz
C.
2kHz
D.
4Khz
3.
Negative feed back in amplifiers is used to
A.
Improves the SNR at the input
B.
Improves the SNR at the output
C.
Reduces
distortion
D.
Doesn’t effect the SNR at the output
4.
In PCM system, if the quantization levels are
increased from 2 to 8, the relative bandwidth requirement will.
A.
remain
same
B.
be
doubled
C.
be tripled
D.
become
four times
5.
Fulladder consists of
A.
1 halfadder and 1 AND gate
B.
2 Halfadders and 1 XOR gate
C.
1 Halfadder and 1 OR gate
D.
2
Halfadders and 1 OR gate
6.
Flipflop is a
A.
Monostable
B.
Bistable
C.
Astable
D.
None of these
7.
For a 8 bit counter the number of filpflops
required is
A.
2
B.
4
C.
3
D.
1
8.
In 8085 microprocessor The data bus has
A.
Unidirectional
B.
Bi-directional
C.
Both
D.
None of these
9.
The number of hardware interrupts in 8085 Microprocessors
A.
2
B.
4
C.
3
D.
5
10.
Which of the following is used for Wider
bandwidth in amplifiers
A.
Cascade connection
B.
Darlington
C.
Cascode
connection
D.
Both A and B
11.
When modulation changed from 0 to 1 then power
increases by
A.
20%
B.
40%
C.
50%
D.
90%
12.
The highest modulation frequency typically used
in AM broadcast is
A.
5KHz
B.
10kHz
C.
15kHz
D.
22kHz
13.
Time division multiplexing used in
A.
Analog communication
B.
Digital
communication
C.
Both A and B
D.
None of these
14.
In a delta modulation the slope overload and
Granular noise occurs when
A.
Δ small an Δ small
B.
Δ large and Δ small
C.
Δ small and Δ large
D.
Δ large and Δ large
15.
Convert decimal number (0.8125)10 to
a binary number
A.
(0.1101)2
B.
(0.1001)2
C.
(0.1100)2
D.
(0.1111)2
16.
Gray code is also called as
A.
Cyclic code
B.
Reflected code
C.
Both
A and B
D.
None of these
17.
Common base
amplifier has
A.
High input impedance
B.
High
output impedance
C.
Low output impedance
D.
None
18.
In negative feedback the distortion will
A.
Increase
B.
Decrease
C.
Some times increase some times decrease
D.
None of the above
19.
Barkausens criteria is
A.
Aβ=1
B.
Aβ=-1
C.
Both A and B
D.
None
20.
Which of the following is more stable
A.
Wien bridge oscillator
B.
Crystal
oscillator
C.
RC oscillatory
D.
Colpitts Oscillator
21.
The forbidden energy gap for germanium atom
A.
1.1 ev
B.
0.7
ev
C.
0.3 ev
D.
None
22.
Maxwell’s curl equation for state magnetic field
is given by
A.
ΔxB=μ0J
B.
ΔxB=0
C.
Δ.B=μ0J
D.
ΔxB=μ0/J
23.
For reflection coefficient ρ=0.5,VSWR is
A.
2
B.
3
C.
4
D.
8
24.
The unit of μ0ε0
is
A.
Farad henry
B.
Meter2/sec2
C.
Amp-sec
D.
None
25.
A low loss transmission line has
A.
R=ωl, G=ωC
B.
R<<ωL, G<<ωC
C.
R>>ωL,
G>>ωC
D.
None
26.
Which of the following has longest wavelength
A.
HF
B.
VHF
C.
UHF
D.
SHF
27.
For a good conductor, the skin depth varies:
A.
Directly as frequency f
B.
Directly as √f
C.
Inversely
as √f
D.
None
28.
An antenna that is circularly polarized is
A.
Helical
B.
Yagi-uda
C.
Parabolic
D.
Small circular loop
29.
In series resonance circuit the voltage source
is
A.
Low
resistance
B.
High resistance
C.
Zero resistance
D.
None of the above
30.
A network is non linear if it doesn’t satisfy
A.
Homogeneity
B.
Superposition theorem
C.
Associative condition
D.
Both
A and B
31.
The gray code for number 6 is
A.
1100
B.
1001
C.
0101
D.
0110
32.
What is the addressing mode used in instruction
LDA 0345
A.
Direct
B.
Indirect
C.
Immediate
D.
Indexed
33.
How many modes of operations are there in 8255
PPI?
A.
1
B.
2
C.
3
D.
4
34.
Which of the following has lowest efficiency
A.
Class
A
B.
Class B
C.
Class AB
D.
Class C
35.
The differential amplifier has a differential
gain of 20000 CMRR=80dB. The common mode gain is
A.
2
B.
1
C.
0.5
D.
0
36.
Super-beta transistor is a
A.
Cascade configuration
B.
Cascode configuration
C.
Darlington
configuration
D.
Matched pair
37.
To eliminate ghosts in the picture
A.
Use a longer transmission line
B.
Connect a booster
C.
Change
the antenna orientation or location
D.
Twist the transmission line
38.
Vividhbharatiprogramme is transmitted in
A.
Short waves
B.
Medium
frequency
C.
Very high frequency
D.
None
39.
The double energy transients occur in the
A.
R-L circuit
B.
R-C circuit
C.
Pure inductive circuit
D.
R-L-C
circuit
40.
The unit of flux is
A.
Weber
B.
Tesla
C.
Joule
D.
Weber/m2
41.
The transfer function H(s)=(s2-5s+100)/s2+5s+100
represents
A.
A high pass filter
B.
A band elimination filter
C.
A resonator
D.
An
all pass filter
42.
Double spotting in superhetrodyne receiver is
caused by
A.
Poor
front-end rejection
B.
Misalignment of receiver
C.
Detuning of one or more IF stages
D.
Non-functioning of AGC
43.
The ratio of distance between cochannel to
radius of the cell (D/R)is
A.
N
B.
√N
C.
3√N
D.
√(3N)
44.
MAHO stands for
A.
Mobile additive hand off
B.
Mobile
assisted Hand off
C.
Mounted additive hand off
D.
None of the above
45.
Traffic intensity is measured by
A.
Traffic
B.
Erlangs
C.
Seconds
D.
Decibels
46.
Frequency selective fading means
A.
Band width of the signal is greater than the
band width of the channel
B.
Delay speed is greater than symbol speed
C.
Both
A and B
D.
None of these
47.
HLR stands for
A.
Home localized rectifier
B.
Home
location register
C.
Home loyality register
D.
None
48.
A receiver has poor if selectivity,it will
therefore also have poor
A.
Blocking
B.
Double spotting
C.
Diversity reception
D.
Sensitivity
49.
The number of lines per second in the US
monochrome TV system
A.
31,500
B.
15,750
C.
63.5
D.
525
50.
An LED made using GaAs emits radiation in
A.
Visible
region
B.
Ultraviolet region
C.
Infrared region
D.
Microwave frequency region
Subscribe to:
Post Comments
(
Atom
)
No comments :
Post a Comment