Electronics and Communication Engineering (ECE)

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

• a)
  2
• b)
  1
• c)
  e^-1/2
• d)
  e

• a)
  1 time
• b)
  10 times
• c)
  11 times
• d)
  infinite times

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

• a)
  -2 V,6/5Ω
• b)
  2 V,5/6Ω
• c)
  1 V,5/6Ω
• d)
  -1 V,6/5Ω

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

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

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

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

   then find 

• a)
  √3
• b)
  1 / 3
• c)
  3  
• d)
  None of these

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

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

A MUX network is shown in fig.

Que: Z₂ = ?

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

• a)
  1
• b)
  2
• c)
   3
• d)
   No error

• a)
  reciprocity theorem
• b)
  principle of maximum power transfer
• c)
  both (a) and (b)
• d)
  none of the above

  along the straight line from 

• a)
  
• b)
  
• c)
  
• d)
  

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

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

Choose the correct sequence :

• a)
  a
• b)
  b
• c)
  c
• d)
  d

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    

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

In the given circuit, the moving-coil meter gives full-scale deflection reading when the average current
flowing through it is 1mA. The moving coil meter has internal resistance of 50?. Find the value of R that results meter a full scale deflection.

• a)
  9950?
• b)
  1566.5?
• c)
  3133?
• d)
  6266?

• a)
  1/12
• b)
  12
• c)
  64/3
• d)
  16/3

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

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

Find the rank of matrix 

• a)
   4  
• b)
  3  
• c)
  2  
• d)
  None of these

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

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.

In the circuit shown below, assume that the diodes D₁ and D₂ are ideal. The average value of voltage V_ab (in
volts) across the terminals a and b is

• a)
  2 Volt
• b)
  0 Volt
• c)
  -2 Volt
• d)
  4 Volt

In the diagram EC and FB are the two rays parallel to the mirror principal axis. Find the condition on q for which constructive interference at point B occurs between the ray ECB and incident ray FB, given AB = d?

• a)
   
• b)
  
• c)
  
• d)
  

If the function    is continuous at x = 0 then find f(0)?

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

• 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

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

• 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

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

• a)
  
• b)
  
• c)
  
• d)
  

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

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

In the circuit shown below, the voltage source has been connected for a long time enough for steady state condition to be reached. At time t=0, switch S is opened. Then open circuit voltage across AB is

• a)
  V.e ^{- (R / L)}
• b)
  V + V.e^-R/L
• c)
  V
• d)
  o

• a)
   The potential biases has disappeared
• b)
  No. of holes diffusing from P-side to N-side equals the no. of electrons diffusing from N-side to P-side
• c)
  Total current crossing Junction from P-side to N-side equals the total current crossing Junction from N-side top-side
• d)
  No carriers cross the Junction

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

• 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.

• a)
   8      
• b)
   6        
• c)
   8 m   
• d)
   6π

• a)
  2 x 10¹⁶ cm^-3
• b)
  4 x 10¹⁶ cm^-3
• c)
  2 x 10¹⁸ cm^-3
• d)
  4 x 10¹⁸ cm^-3

• a)
  1
• b)
  2
• c)
  4
• d)
  8

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

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

• a)
   

  1010 kHz
• b)
  1455 kHz
• c)
  1910 kHz
• d)
  545 kHz

• a)
  more accurate but less stable
• b)
  less accurate but more stable
• c)
  more accurate as well as more stable
• d)
  less accurate as well as less stable