Company: Cognizant Technology Solutions

1)Kirchoff’s nodal equations based on the principle of
a)conservation of energy
b)conservation of charge
c)conservation of power
d)impedance matching
2)networks connected in series following pairs are most suitable for
1. Abcd parameters
2. Z parameters
3. Y
4. H
3)For ideal filter , phase characteristics are
1. Line
2. Exponential
3. Logarthimic
4)Quality factor of rlc series ckt is
5)If geta=1, the roots of cequ are
1. Real
2. Imaginary
3. Real and repeated
4. Comp and conjugate
6)For a 6db attenuator , if input power is 100MW ,o/p power will be =?
7)F(t)=t e at, F(S)=?
8)F(S)=1/(s+a)2, f(t) =?
9)For a perfectly matched tx line , reflection coefficient=?
10)Radiation pattern of isotropic radiator is
1. Figure of eight
2. Circular
3. Ellipse
4. Sinx/x function
11)Which of the following modulation is non linear
1. A.M
2. SSB
3. FM
4. PM
12)Amplitude limiter essentially a
1. Square ckt
2. Clipper
3. Clamper
4. Rectifier
13)Waveguide acts as
1. Lpf
2. Bpf
3. Hpf
4. Apf
14)x-band rangeis
15)reflection coefficient is zero , then the line is
1. Open ckt
2. Short ckt
3. Infinite
4. Terminated by 50ohms
16)Which of the following microphone provide high directivity
1. Carbone
2. Condenser
3. Ribbon
4. Crystal
17)Dynamic memory cells are constructed using
18)Which of the following is most efficient
1. Ppm
2. Pdm
3. Pam
4. Qam
19)Which of the following has higher bandwidth
1. Pam
2. Pdm
3. Ppm
4. Am
20)Essential channel capacity is a measure of
21)Lossless line condition is?
22)Typical bit rate of keyboard devices ?
23)16 in octal s/m is?
24)No of bits represents 16 is
25)16 bit width ,8085 mapps ans 64kilobytes
26)Which of the following flipflop doesn’t have race problem?
27)Memory word size of 8085 microprocessor?
28)Flip flop used in shift register
29)And gate
30)Static electricity is formed for?
31)Cc has current gain and input impedance ?
32)Dominant mode TE10
33)Wave length in waveguide equal to ,greater than , lessthan ,independent of free space wave length
34)Half adder has how many ips and ops
35)Parallel to serial converter
36)Semiconductor memories
1. Volatile
2. Non volatile
37)Magnetron is
1. Highpower microwave oscillator
2. Lowpower microwave oscillator
3. High gain amplifier
4. Low power amplifier
38)Bethe-hole coupler uses
1. Ferrite material
2. Dielectric
3. Gunn diode
39)Power gain=40
Voltage gain=200
Current gain=?
40)Bandwidth =resonant frequency/qualityfactor
41)Differentiation of u(t)?
42)Freespace impedance?
43)Resonant frequency of rlc ckt is ?
44)Tfunction=k(s+1)/s(s-2+j3)(s-2-j3), no of poles=?
45)Tfuncion 1-s/1+s , it is known as
1. Low pass system
2. All pass system
3. High pass system
4. Band pass system
46)G=k/s2(1+sT)then order and type=?
47)Which of the following component is passive and reciprocal
1. Circulator
2. Isolator
3. Pin diode attenatur
4. Direction coupler
48)Broad side array interelement phase shift is
1. 180
2. 90
3. 0
4. 45
49)R=100ohms,C=100pf, TIME CONST=?
50)Isotropic antenna gain is
1. 0db
2. 6db
3. 3db
4. 10db
51)In one timeconstant the final value increases by _____________value
53)s-equation of L DI/DT
1. 1/ls
2. 1/ls2
3. Ls
4. Ls2
54)In a CE amplifier ,if a C.E voltage increase
55)Transfer function has 2poles on L.HS PLANE and 2zeros on r h s plane this results
1. Lpf
2. Hpf
3. Bpf
4. Allpass
56)The gain at corner frequency is?
57)t.v s/m am- picture,fm-sound
58)code used in teleprinter
59)bandwidth of telephoneis
60)bit is aunit of
61)when 2 nlw are connected in parallel
z-parameter add
abcd parameter
62)beamwidth of antenna is
1. Inversely Proportional aperturelength
2. Directly proportional aperture length
3. Square root of frequency
4. Independent of aperture length
63)Convolution of two u(t)?
64)T function H(s)=1/(s+1),h(f)=?
65)Typical q factor of crystal oscillator
66)In pnp transistor saturation current is due to
67)When both junction of a transistor is forward biased then it is said to be in
68)50ohms line matched to 200 ohms load through quarter wavelength transmission , the characteristic impedance of matched line should be
1. 75ohms
2. 100ohms
3. 200ohms
4. 50ohms
69)F(s)=1/s2, then f(t)?
70)Fourier series expansion of a even periodic function contains ?
1. Cosine and const term
2. Only constant terms
3. Sine terms and constants
4. Only sine terms
71)If ip of ckt is sine , the steady state op willbe exponentially decay with time const,sin , damped sinusoidal
72)Power gain of emitter follower ?
73)Highest voltage gain can be obtained from
1. Cc
2. Ce
3. Cb
4. Ce and cb
74)Differentiation of time domain is equal to
1. Division by s in freq domain
2. Multiplication by s in freq domain
3. Multiplication by e-st
4. Multiplication by 1/e-st
75)Standard rect waveguide width to height ratio
1. 3:1
2. 3:2
3. 2:1
4. 1:2
76)Which is micro wave oscillator
1. Magnetron
2. Twt
3. Two cavity klystron
4. Laser
77)If transmission line open ckt then vswr?
78)Pn junction reversebiased then,
79)Hall effect used to measure?
80)P type semiconductor properties?