Multiple Choice questions for ECE

Answers : 

81 b 101 A 121 C 141 C
82 a 102 B 122 B 142 D
83 a 103 A 123 A 143 A
84 C 104 D 124 C 144 C
85 A 105 A 125 A 145 A
86 B 106 C 126 D 146 B
87 C 107 B 127 A 147 A
88 C 108 D 128 B 148 A
89 A 109 B 129 D 149 A
90 A 110 A 130 B 150 A
91 A 111 B 131 C
92 C 112 B 132 B
93 C 113 A 133 C
94 D 114 B 134 B
95 D 115 A 135 D
96 A 116 A 136 B
97 A 117 B 137 D
98 C 118 A 138 C
99 D 119 B 139 A
100 A 120 A 140 D

98) In the Frequency Transformations of the analog domain the transformation is
a) Low Pass to Lowpass                                               b)Lowpass to Highpass                              c)Lowpass to Bandpass                                                d)Lowpass to Bandreject

99)In the Frequency Transformations of the analog domain the transformation is
a) Low Pass to Lowpass                                               b)Lowpass to Highpass
c)Lowpass to Bandpass                                               d)Lowpass to Bandreject

100) The magnitude response of the following filter decreases monotonically as frequency increases
a)Butterworth Filter                                        b)Chebyshev type - 1
c)Chebyshev type - 2                                       d)FIR Filter

101)The transition band is more in
a)Butterworth Filter                                        b)Chebyshev type - 1
c)Chebyshev type - 2                                       d)FIR Filter

102)The poles of Butterworth filter lies on
a)sphere                                                                      b)circle
c)ellipse                                                                       d)parabola

103) I I R digital filters are of the following nature
a)Recursive                                                     b)Non Recursive
c)Reversive                                                     d)Non Reversive

104) In I I R digital filter the present output depends on
a)Present and previous Inputs only                b)Present input and previous outputs only
c)Present input only                                        d)Present Input, Previous input and output

105). Which of the following is best suited for I I R filter when compared with the FIR filter
a)Lower sidelobes in stopband                                   b)Higher Sidelobes in stopband
c)Lower sidelobes in Passband                                   d)No sidelobes in stopband

106) In the case of I I R filter which of the following is true if the phase distortion is tolerable
a)More parameters for design                       b)More memory requirement
c)Lower computational Complexity               d)Higher computational complexity

107). A causal and stable I I R filter has
a)Linear phase                                                            b)No Linear phase
c)Linear amplitude                                         d)No Amplitude
108)Neither the Impulse response nor the phase response of the analog filter is a)Preserved in the digital filter in the following method
b)The method of mapping of differentials
c)Impulse invariant method
d)Bilinear transformation Matched Z - transformation technique

109). Out of the given I I R filters the following filter is the efficient one
a) Circular filter                                              b)Elliptical filter
c)Rectangular filter                                        d)Chebyshev filter

110)What is the disadvantage of impulse invariant method
a) Aliasing                                                       b)one to one mapping
c)anti aliasing                                                 d)warping

111)Which of the I I R Filter design method is antialiasing method?
a)The method of mapping of differentials                 b)Impulse invariant method
c)Bilinear transformation                                           d)Matched Z - transformation technique

112) The nonlinear relation between the analog and digital frequencies is called
a)aliasing                                                        b)warping
c)prewarping                                                  d)antialiasing

113) The most common technique for the design of I I R Digital filter is
a)Direct Method                                             b)In direct method
c)Recursive method                                        d)non recursive method

114)Pre-emphasis in FM used at
a) Receiving end                                             b) transmitting end
c) In the channel                                             d) Before the demodulation

115)De-emphasis circuit resembles a
a) LPF                          b)HPF                           c)BPF                          d)BRF

116)Most of the power in AM signal lies in its
a)Carrier                     b)LSB                          c)USB                          d)LSB&USB

117)All commerical receivers employ IF between
a)200  to 300KHZ                                                        b)455KHZ to 465KHZ
c)740KHZ to 840KHZ                                                   d)12 to 13KHZ

118)TDM can be implemented using
A)PAM                         B) AM                          C)FM                          D)VSB-AM

119)A medium wave transmitter works in the frequency range
A)2.5 to 7.5MHZ         B)500 to 1600KHZ       C)7.5 to 30MHZ          D)100 to 300KHZ

120)Three point tracking achieved with
A)Padder capacitor                                         B)Double spotting
C)Blocking                                                       D)Double conversion

121)Quatization noise occurs in
A)TDM                         B)FDM                        C)PCM             D)PPM

122)Which of the following is used to convert PPM into PWM
A)Clipping circuit                                            B)Bistable multivibrator
C)Astable multivibrator                                  D)Clamping circuit

123)PWM signal can be demodulated using
A)Integrator and LPF                                        B)Differentiator and LPF
 C) Integrator and HPF                                                D) Differentiator and HPF

124)PPM can be generated from
A)AM                           B)FM                          C)PWM            D)PM

125)Noise limiter is analogous to
A)clipper                     B)Clamper                   C)Rectifier                   D)AGC

126)Boosting high frequency components in modulating signal is called
A)Echo suppressing                 B)Attenauting              C)Tone correction      D)Pre-emphasis

127)The ability of the receiver to respond to the weakest signal is called
A)Sensitivity                B)Selectivity               C)Fidelity         D)Image frequency rejection

128)Companding is used
A)To overcome quatization noise in PCM                             
B)To protect small signals in PCM from quatization noise
C)In PCM receivers to reduce impulse noise
D)To increase the power contant of the modulated signal

129)Pulse communication system that is inherently highly immune to noise is
A)PWM                        B)PPM             C)PPM                                    D)PCM

130)To undo the distortion caused by the channel,which of the following can be used
A)Amplifier                 B)Equalizer      C)Attenautor               D)Clamper

131)In a FM receiver the stage between IF amplifier and detector is
A)Mixer                      B)Limiter         C)AF amplifier                        D)Local oscillator

132)The ability of the receiver to distinguish the wanted and unwanted signals is
A)Sensitivity                B)Selectivity    C)Fidelity                    D)S/N ratio

133)The component to produce the AM at RF frequencies is
A)Varactor                  B)Thermistor   C)PIN diode                D)Transistor

134)COHO in MTI radar operates
A)At supply frequency                                     B)At intermediate frequency
C)Pulse repetition frequency                                       D)Station frequency
135)A rectangular waveguide behaves like a
136)PPI in radar system stands for
A)Plan position indicator                                B)Pulse position indicator
 C)Plan position image                                     D)Prior position indentification

137)The doppler effect is used in
A)MTI                          B)CW                          C)FM                          D)Radar altimeter

138)COHO stands for
A)Coherent output                                          B)Counter housed oscillator
C)Coherent local oscillator                             D)Carrier oscillator and harteley oscillator

139)Large antenna used in radar bacause it
A)gives higher gain                                         B)gives lesser side lobes
C)increase beam width                                   D) increase band width

140)A biostatic radar has
A)one antenna for transmitting and as well as for receiving
B)two antennas for receiving the signal
C) two antennas for transmitting signal        
D) transmitting and receiving antennas

141)Blind speed causes target to appear
A)moving uniformly                                        B)moving irregularly
C)stationary                                                    D)intermittently

142)A radar system cannot be used
A)to detect moving objects B)to detect trajectory of moving objects C)to detect aircraft D)to detect storms

143)Most of the aircraft surveillance radars operate in
A)L Band                      B) C Band                    C) S Band                     D) X Band

144)Which of the following is not a display method
A)PPI                B)Computer feeding               C)Monopulse conical scanning           D)A Scope

145)The antenna used for radar as
A)Paraboloidal antenna                                              B)isotropic radiator
C)resonant antenna                                                    D)whip antenna

146)The distance of 2000 yards is called
A)satellite mile B)radar mile C)1 yard D)1 Km

147)The duplexer consists of one---and another---switches
A)TR and ATR switches                                               B)KR and TR
C)ART and TR                                                              D)Diode and transistor

148)The echoes from the target are
A)repetitive                 B)once             C)two times repeated            D) four times repeated

149)Beacon is used instrument-----system for aircraft
A)Landing                    B)Lifting                      C)Consume                 D)Damage

150)In MTI coho is used for the generation of

A)RF Signal                  B) AF Signal                 C) AM Signal               D) FM Signal
Multiple Choice questions for ECE Multiple Choice questions for ECE Reviewed by Suresh Bojja on 10/25/2015 03:35:00 AM Rating: 5
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