Electronics and Communication Engineering (ECE)

• a)
  1
• b)
  2
• c)
  4
• d)
  8

A lossless coaxial line having inner and outer diameters 5 cm and 10 cm respectively is used as a transmission line for excitation of an antenna with    .The characteristic impedance is ----------------------    (ohms)

• a)
  87.1
• b)
  458
• c)
  25.01
• d)
  0.21

Which of the quantities is nearest to the value of

• a)
  1
• b)
  1.001
• c)
  1.002
• d)
  1.003
• e)
  1.000006

• a)
  bandwidth of frequencies having output with in � 1 dB of the output at 1000 Hz
• b)
  bandwidth of frequencies having output with in � 3 dB of the output at 1000 Hz
• c)
  bandwidth of frequencies having output with in � 1 dB of the output at 500 Hz
• d)
  bandwidth of frequencies having output with in � 3 dB of the output at 500 Hz

• a)
  Human progress and security are positively associated with environmental security
• b)
  Human progress is contradictory to environmental security.
• c)
  Human security is contradictory to environmental security.
• d)
  Human progress depends upon environmental security

If wave form is given only for I period then

 

Q. Waveform x (t) is

 

• a)
  an even function with half wave symmetry.
• b)
  An odd function with half wave symmetry.
• c)
  an even function with no half wave symmetry.
• d)
  An odd function with no half wave symmetry.

• a)
   0.5  
• b)
   0.6  
• c)
   0.7  
• d)
   None of these

• a)
  3.6 V
• b)
  9.8 V
• c)
  7.2 V
• d)
  12.3 V

• A:

  high only when A = 0, B = 0

• B:

  high only when A = 0, B = 1

• C:

  high only when A = 1, B = 0

• D:

  high for all values of A and B

The answer is A.

 Match List-I (Combinational Circuits) with List-ll (Applications) and select the correct answer using the codes given below the lists:

List-I
A. Decoder
B. Multiplexer
C. Encoder
D. Demultiplexer

List-ll
1. Serial to parallel converter
2. Digital to analog converter
3. Parallel to serial converter
4. Analog to digital converter

• a)
  a
• b)
  b
• c)
  c
• d)
  d

• a)
  Positive and has a large value
• b)
  Negative and has a large value
• c)
  Positive and has a small value
• d)
  Negative and has a small value

With 10 V dc connected at port A in the linear nonreciprocal two-port network
shown below, the following were observed :

Q.

For the same network, with 6 V dc connected at port A, 1Ω connected at port B
draws 7/3 A. If 8 V dc is connected to port A, the open circuit voltage at port B is

• a)
  6 V
• b)
  7V
• c)
  8 V
• d)
  9V

• a)
  0
• b)
  1
• c)
  2
• d)
  3

With 10 V dc connected at port A in the linear nonreciprocal two-port network
shown below, the following were observed :

(i) 1Ω connected at port B draws a current of 3A
(ii) 2.5 Ω connected at port B draws a current of 2A

Q.

With 10 V dc connected at port A, the current drawn by 7 Ω connected at port B
is

• a)
  3/7 A
• b)
  5/7 A
• c)
  1A
• d)
  9/7 A

• a)
  Equal to 1             
• b)
  Less than 1             
• c)
  Greater than 1         
• d)
  Equal to 5 ​

• a)
   1 & 3
• b)
  2 & 4
• c)
  1, 3 & 4
• d)
  1,2,3 & 4

• a)
  impartial
• b)
  argumentative
• c)
  separated
• d)
  hostile

The pole-zero diagram of a causal and stable discrete-time system is shown in the figure. The
zero at the origin has multiplicity 4. The impulse response of the system is h[n]. If h[0] = 1,
we can conclude

• a)
  h[n] is real for all n
• b)
  h[n] is purely imaginary for all n
• c)
  h[n] is real for only even n
• d)
  h[n] is purely imaginary for only odd n

• a)
  3
• b)
  2
• c)
  4
• d)
  Limit does not exist

The 3-terminal linear voltage regulator is connected to a 10 ohm load resistor as shown in figure. If V_in is 10 volt, what is power dissipated in the Si transistor.

• a)
  0.6 W
• b)
  2.4 W
• c)
  4.2 W
• d)
  5.4 W

• a)
  distance and ignorance
• b)
  language and cost
• c)
  distance and language
• d)
  distance and cost

• a)
  hardware program
• b)
  source program
• c)
  object program
• d)
  both (a) and (c)

• a)
  Reference input
• b)
  Reference output
• c)
  Output and feedback signal
• d)
  Input and feedback signal

Consider the following ‘3’ transfer functions.

Among these minimum phase system (s) i s/are

• a)
  1 and 2    
• b)
  1 and 3
• c)
  1 only    
• d)
  1,2 and 3

• a)
  which has zeros only in the left-half s-plane
• b)
  which has poles in the right-half s-plane
• c)
  which has zeros in the right-half s-plane
• d)
  which has poles in the left-half s-plane

• a)
  49.3 nF
• b)
  38.7 nF
• c)
  77.4 nF
• d)
  98.6 nF

• a)
  10111
• b)
  10011
• c)
  10110
• d)
  10010

A MUX network is shown in fig.

Que: Z₂ = ?

• a)
  ab + bc + ca
• b)
  a + b + c
• c)
  abc
• d)
  

• a)
   eclipses
• b)
   dominates
• c)
   overshadows
• d)
   subdues

• a)
  could have, been
• b)
  would have, being
• c)
  had, have
• d)
  had been, been

• a)
  Both the P-region and the N-region are heavily doped
• b)
  The N-region is heavily doped compared to the P-region
• c)
  The P-region is heavily doped compared to the N-region
• d)
  An intrinsic silicon region is inserted between the P-region and the N-region

• a)
  Eddy current losses are higher
• b)
  Mass of moving system
  becomes higher
• c)
  The magnetic field produced by
  eddy currents introduce error
• d)
  Operating field is weak due to
  air cored.

• a)
  1/2    
• b)
  2.20 x10^-5
• c)
  4.39 x10^-10    
• d)
  0.005

• a)
  20 rad/s
• b)
  20 Hz
• c)
  40 rad/s
• d)
  40 Hz

• a)
  TE₁₀ < TE₂₀ < TE₀₁ < TM₁₁
• b)
  TE₁₀ < TE_o1 < TE₂₀ < TM₁₁
• c)
  TE ₁₁ < TE₀₁ < TE₂₀ < TM ₁₀
• d)
  TE₀₁ < TE₁₀ < TE₂₀ < TM₁₁

• a)
  
• b)
  
• c)
  
• d)
   None of these

• a)
  b
• b)
  a
• c)
  b/a
• d)
  a/b

• a)
  Synchronousdetector       
• b)
  Square law demodulator
• c)
  Envelope detector
• d)
  FM receiver

• a)
  easier, than
• b)
  most easy, than
• c)
  easier, from
• d)
  easiest, from

• a)
  0.77 eV
• b)
  0.67 eV
• c)
  0.57 eV
• d)
  0.47 eV

• a)
  − 200 ε₀
• b)
  − 200/ε₀
• c)
  200 ε₀
• d)
  − 240 ε₀

The Eigen values of the matrix 

• a)
  1, 1, 2
• b)
  1, 2, 2
• c)
  1, 2, 3
• d)
  None of these

• a)
  (- 1)^k δ(k)                             
• b)
  δ(k) - (- 1)^k
• c)
  (-1)^k u(k)           
• d)
  u(k) - (- 1)^k

• a)
  all probabilities are equal
• b)
  one of the probabilities equal to 1 and two others are zero
• c)
  the probabilities are 1/2, 1/4 and 1/2
• d)
  the two of the probabilities are 1/2 each and other zero

The circuit shown below is the

• a)
  Full adder
• b)
  Full subtractor
• c)
  Parity checker
• d)
  None of these

• a)
  a and b
• b)
  b and c
• c)
  b, c, and d
• d)
  all

• a)
  d.c. ground point
• b)
  must be floating
• c)
  The most negative voltage available in the circuit
• d)
  The most positive voltage available in the circuit

• a)
   She is smart enough to take care of herself in Bombay
• b)
   She is enough smart to take care of oneself in Bombay
• c)
   She is enough smart to take care of herself in Bombay
• d)
   She is smart enough to take care of oneself in Bombay

• a)
  
• b)
  
• c)
  
• d)
  

Match List-I with List-ll and select the correct answer using the codes given below the lists:
List-I 
A. Immersion rod
B. Air conditioner
C. Automatic washing machine
D. Automatic control of traffic
List-ll
1. Open loop control system
2. Closed loop control system
3. Neither a closed loop nor an open loop system

• a)
  a
• b)
  b
• c)
  c
• d)
  d

• a)
  Imaginary
• b)
  Conjugate anti-symmetric
• c)
  Conjugate symmetric
• d)
  Real

The signal flow graph shown below has M number of forward path and N number of individual loops.

Q. ​What are the values of M and N ?

• a)
  M= 3 and N= 4
• b)
  M = 4 and N = 6
• c)
  M = 4 and N = 4
• d)
  M = 2 and N = 6

Which one of the following is a property of the solutions to the Laplace equation : 

• a)
  The solution have neither maxima nor minima anywhere except at the boundaries
• b)
  The solution are not separable in the coordinates
• c)
  The solution are not continuous
• d)
  The solution are not dependent on the boundary conditions

• a) 
  62Ω
• b) 
  43Ω
• c) 
  72Ω
• d) 
  81Ω

• a)
  83 mV
• b)
  59 mV
• c)
  43 mV
• d)
  31 mV

If saturation currents of 2 diodes are 1 µA and 2 µA.
If break down voltages of diode are same and are equal to 100 volt, what is value of current in D1.

Q.

If V = 90 volt

• a)
  0 µA
• b)
  1 µA
• c)
   1.5 µA
• d)
   2 µA    

• a)
  requested that
• b)
  should be give
• c)
  the driving test
• d)
  instead of tomorrow

• a)
  Both A and R are correct and R is the correct explanation of A
• b)
  Both A and R are correct and R is not the correct explanation of A
• c)
   A is true and R is false
• d)
  A is false and R is true

• a)
  2x
• b)
  −2x
• c)
  2|x|
• d)
  None of these

• a)
  1.3 x 10^-7 s
• b)
  1.3 x 10^-4 s
• c)
  6.5 x 10^-8​ s
• d)
  6.5 x 10^-4​ s