UGC NET Electronics Science Exam - December 2006 : Quiz & Solutions

Test your Preparation by solving UGC - NET 2006 (Electronics Science) Exam Question Paper :

1. An electron rising through a potential of 250 V will acquire an energy of :
a. 250 eV
b. 800 eV
c. 250 J
d. 800 J

2. If the amount of impurity, either donor type or acceptor type added to the intrinsic semiconductor is controlled to 1 part in one million, the conductivity of the sample :
a. increases by a factor 10e3
b. reduces by a factor 10e-3
c. increases by a factor 10e6
d. reduces by a factor 10e-6

3. The fourier transform of a function on X (t) is X ( f ). The fourier transform of dX ( f )/df will be :
a. dX ( f )/df
b. j 2p f x ( f )
c. j f x ( f )
d. X ( f )/jf

4. Laplace transform and Fourier integrals are related through :
a. frequency domain
b. time domain
c. both frequency and time domain
d. none

5. A clamper circuit :
(i) adds or subtracts a dc voltage to or from a waveform
(ii) does not change the shape of the waveform
(iii) amplifies the waveform

a. (i) and (ii) are correct
b. (i) and (iii) are correct
c. (ii) and (iii) are correct
d. (i), (ii) and (iii) are correct

6. The amplifier gain with positive feedback is given by :
a. A/1+Aß
b. A/1-Aß
c. A/1-ß
ß/1-A

7. A ring counter consisting of five flip flop will have :
a. 5 states
b. 10 states
c. 32 states
d. infinite states

8. Which one of the following can be used as parallel to series converter ?
a. Decoder
b. Encoder
c. Digital counter
d. Multiplexer

9. An interrupt in which the external device supplies its address as well as the interrupt request, is known as :
a. vectored interrupt
b. maskable interrupt
c. polled interrupt
d. non-maskable interrupt

10. In 8085 microprocessor, the value of the most significant bit of the result following the execution of any arithmetic of Boolean instruction is stored in the :
a. carry status flag
b. auxiliary carry status flag
c. sign status flag
d. zero status flag

11. An instruction that can be recognized and used without translation must be written in :
a. Source code
b. Machine code
c. Basic language
d. Assembly code

12. What is the name of the arrangement where by several central processing units share one memory ?
a. Multitasking
b. Multiprogramming
c. Multiprocessing
d. Concurrent programming

13. The angle for which there is no reflection and the incident wave is vertically polarized is known as :
a. Steradian angle
b. Reflection angle
c. Brewster’s angle
d. Critical angle

14. The characteristic impedance of a transmission line is given by :
a.
b.
c.
d.

15. A PLL can be used to demodulate :
a. PAM signals
b. PCM signals
c. PM signals
d. DSB-SC signals

16. The main function of balanced modulator is to :
a. produce balanced modulation of a carrier wave
b. produce 100 percent modulation
c. suppress carrier signal in order to create a single side band or double side band
d. limit noise picked up a receiver

17. An SCR can be termed as :
a. DC switch
b. AC switch
c. Both DC and AC switch
d. Square wave switch

18. Fiber optics communication offers the largest bandwidth in the range of :
a. 10e10
b. 10e6
c. 10e14
d. 10e20

19. Silicon photosensors have their maximum spectral response in the :
a. infrared region
b. ultraviolet region
c. visible region
d. X-ray region

20. Open loop transfer function is given by the system is ::
a. is stable
b. is unstable
c. is marginally stable
d. is absolutely stable

21. Match List-I with List-II and select the correct answer using the codes given below the lists :

             List-I                           List-II
    (a) Zener Diode                (i)  Negative resistance
    (b) Tunnel Diode              (ii)  High current gain
    (c) Gunn diode               (iii)  voltage regulation
    (d) PIN diode                 (iv)  High input impedance

a. (iii) (i),(ii) (iv) (i)
b (iv) (ii),(iv) (iv) (i)
c. (iv) (i),(iii),(iv) (i) (iii)
d. (iii) (i),(ii),(iv) (iv) (i)

22. Match List-I and List-II and select the correct answer using the codes given below the lists :

             List-I                           List-II
    (a) Venturi tube                 (i)   Displacement
    (b) Optical tachometer           (ii)  Pressure
    (c) LVDT                         (iii) Flow
    (d) Pirani Gauge                 (iv)  Velocity

a. (i) (iv) (iii) (ii)
b. (iii) (ii) (i) (iv)
c. (i) (ii) (iii) (iv)
d. (iii) (iv) (i) (ii)

23. Match List-I with List-II and select the correct answer using the codes given below the lists :

            List-I                                       List-II
     (a) Frequency Modulation                       (i)  Envelop detection
     (b) Double sideband suppressed carrier signal  (ii) Companding 
     (c) PCM                                        (iii)Balance Modulator
     (d) Amplitude Modulation                       (iv) Pre-emphasis and deemphasis

a. (i) (ii) (iii) (iv)
b. (i) (ii) (iv) (iii)
c. (iv) (iii) (i) (ii)
d. (iv) (iii) (ii) (i)

24. Match List-I and List-II and select the correct answer using the codes given below the lists :

           List-I                           List-II
  (With respect to Magnetron         (With respect to Magnetron peak
average o/p power, dyty cycle)        o/p power in Watts)
    (a) 25 W                          (i)   6250
    (b) 50 W                          (ii)  5000
    (c) 100 W                         (iii) 2500
    (d) 150 W                         (iv)  1250

a. (iv) (iii) (ii) (i)
b. (iii) (iv) (ii) (i)
c. (i) (ii) (iii) (iv)
d. (iv) (iii) (i) (ii)

25. Match List-I and List-II and select the correct answer using the codes given below the lists :

        List-I                           List-II
  
    (a) AND                         (i)   ||
    (b) OR                          (ii)  =!
    (c) NOT                         (iii) &&
    (d) NOT EQUAL                   (iv)  !

a. (ii) (iii) (i) (iv)
b. (iii) (i) (iv) (ii)
c. (iv) (iii) (ii) (i)
d. (i) (ii) (iii) (iv)

26. Match List-I and List-II and select the correct answer using the codes given below the lists :

           List-I                           List-II
  (Status flag w.r.t 8085)             (Bit position)
    (a) Auxillary carry                   (i)   7
    (b) Gign                              (ii)  6
    (c) Zero                              (iii) 4
    (d) Parity                            (iv)  2

a. (i) (ii) (iii) (iv)
b. (ii) (iii) (i) (iv)
c. (i) (ii) (iii) (iv)
d. (iii) (i) (iv) (ii)

27. Match List-I and List-II and select the correct answer using the codes given below the lists :

           List-I                           List-II
  
    (a) Solar Cell                    (i)   Spontaneous emission
    (b) LED                           (ii)  Stimulated emission
    (c) Laser                         (iii) Photovoltaic conversion
    (d) Reflex Klystron               (iv)  Velocity modulation

a. (iii) (i) (ii) (iv)
b. (i) (ii) (iii) (iv)
c. (ii) (iii) (iv) (i)
d. (iv) (i) (ii) (iii)

28. Match List-I and List-II and select the correct answer using the codes given below the lists :

        List-I                           List-II
  
    (a) ROM                    (i)   Volatile memory
    (b) RAM                    (ii)  Non-volatile memory
    (c) Magnetic Memory        (iii) Erasable Programmable Read Only Memory
    (d) EPROM                  (iv)  Permanent memory

a. (i) (ii) (iv) (iii)
b. (ii) (i) (iv) (iii)
c. (iii) (i) (ii) (iv)
d. (iv) (iii) (ii) (i)

29. Match List-I and List-II and select the correct answer using the codes given below the lists :

       List-I                       List-II
  
    (a) Bit                    (i)   16 bit
    (b) Byte                   (ii)  1 bit
    (c) Nibble                 (iii) 4 bit
    (d) 8086                   (iv)  8 bit

a. (ii) (iv) (iii) (i)
b. (i) (iii) (ii) (iv)
c. (iv) (ii) (i) (iii)
d. (iii) (iv) (ii) (i)

30. Match List-I and List-II and select the correct answer using the codes given below the lists :

           List-I                             List-II
  With respect to copper film            Surface resistance
 thickness (A ),resistivity (Ω-cm×10−7)       (Ω / Square)


    (a) 100, 0.52                         (i)   7.25
    (b) 80, 0.58                          (ii)  21.50
    (c) 60, 0.68                          (iii) 5.20
    (d) 40, 0.86                          (iv)  11.33

a. (ii) (iii) (i) (iv)
b. (iii) (i) (iv) (ii)
c. (iv) (i) (iii) (ii)
d. (i) (ii) (iii) (iv)

31. Assertion (A): Silicon is widely used in IC technology.
Reason (R): Silicon technology is less expensive and SiO2 layer can be easily formed on silicon.
a. Both (A) and (R) true and (R) is the correct explanation of (A)
b. Both (A) and (R) true but (R) is not the correct explanation of (A)
c. (A) is true but (R) is false
d. (A) is false but (R) is true

32. Assertion (A) : The greater the ‘Q’ the smaller the bandwidth of a resonant circuit.
Reason (R) : At high frequencies the ‘Q’ of a coil falls due to skin effect.
a. Both (A) and (R) true and (R) is the correct explanation of (A)
b. Both (A) and (R) true but (R) is not the correct explanation of (A)
c. (A) is true but (R) is false
d. (A) is false but (R) is true

33. Assertion (A) : In an Op-Amp circuit when one input terminal of the Op-Amp is grounded, the other terminal becomes virtual ground.
Reason (R) : Input impedance of the Op-Amp is high.
a. Both (A) and (R) true and (R) is the correct explanation of (A)
b. Both (A) and (R) true but (R) is not the correct explanation of (A)
c. (A) is true but (R) is false
d. (A) is false but (R) is true

34. Assertion (A) : Master-Slave JK flip-flop is free from race-around condition.
Reason (R) : Master-Slave uses two JK flip-flops.
a. Both (A) and (R) true and (R) is the correct explanation of (A)
b. Both (A) and (R) true but (R) is not the correct explanation of (A)
c. (A) is true but (R) is false
d. (A) is false but (R) is true

35. Assertion (A) : A processor can reference a memory stack without specifying an address.
Reason (R) : The address is always available and automatically updated in the stack pointer.
a. Both (A) and (R) true and (R) is the correct explanation of (A)
b. Both (A) and (R) true but (R) is not the correct explanation of (A)
c. (A) is true but (R) is false
d. (A) is false but (R) is true

36. Assertion (A) : Subroutines are used in larger programming.
Reason (R) : Program testing at the program development time will be easier.
a. Both (A) and (R) true and (R) is the correct explanation of (A)
b. Both (A) and (R) true but (R) is not the correct explanation of (A)
c. (A) is true but (R) is false
d. (A) is false but (R) is true

37. Assertion (A) : Two cavity Klystron is now-a-days frequently used as microwave amplifier.
Reason (R) : Velocity and current modulation occurs in Klystron
a. Both (A) and (R) true and (R) is the correct explanation of (A)
b. Both (A) and (R) true but (R) is not the correct explanation of (A)
c. (A) is true but (R) is false
d. (A) is false but (R) is true

38. Assertion (A) : A half-adder is faster than full adder.
Reason (R) : A half adder gives only one output while a full adder gives two outputs.
a. Both (A) and (R) true and (R) is the correct explanation of (A)
b. Both (A) and (R) true but (R) is not the correct explanation of (A)
c. (A) is true but (R) is false
d. (A) is false but (R) is true

39. Assertion (A) : Optical fibers have broader bandwidth to conventional copper cables.
Reason (R) : The information carrying capacity of optical fiber is limited by Rayleigh’s scattering loss.
a. Both (A) and (R) true and (R) is the correct explanation of (A)
b. Both (A) and (R) true but (R) is not the correct explanation of (A)
c. (A) is true but (R) is false
d. (A) is false but (R) is true

40. Assertion (A) : Piezoelectric crystals serve as a source of ultrasonic wave.
Reason (R) : The crystals can generate wave having frequencies greater than 20 kHz.
a. Both (A) and (R) true and (R) is the correct explanation of (A)
b. Both (A) and (R) true but (R) is not the correct explanation of (A)
c. (A) is true but (R) is false
d. (A) is false but (R) is true

41. Give sequence of the following interrupts on priority basis from highest to the lowest :
(i) RST 5.5
(ii) RST 6.5
(iii) RST 7.5
(iv) TRAP
a. (i), (ii), (iii), (iv)
b. (ii), (iii), (i), (iv)
c. (iii), (ii), (iv), (i)
d. (iv), (iii), (ii), (i)

42. The highest data rate can be transmitted using the following cables :
(i) Twisted-wire cable
(ii) Co-axial cable
(iii) Fiber-optic cable

a. (iii), (ii), (i)
b. (i), (iii), (ii)
c. (ii), (i), (iii)
d. (i), (ii), (iii)

43. Write down the different computer network from lowest to the highest order :
(i) LAN
(ii) WAN
(iii) MAN

a. (ii), (i), (iii)
b. (iii), (i), (ii)
c. (i), (ii), (iii)
d. (i), (iii), (ii)

44. Consider the following rectifier circuits :
(i) Half-wave rectifier without filter
(ii) Full-wave rectifier without filter
(iii) Full-wave rectifier with series inductance filter
(iv) Full-wave rectifier with capacitance filter
The sequence of these rectifier circuits in decreasing order of their ripple factor is :
a. (iii), (iv), (i), (ii)
b. (i), (iv), (iii), (ii)
c. (iii), (ii), (i), (iv)
d. (i), (ii), (iii), (iv)

45. What is the correct sequence of the following steps for fabrication of monolithic, bipolar junction transistor ?
(i) Emitter diffusion
(ii) Base diffusion
(iii) Buried layer formation
(iv) Epilayer formation
a. (iii), (iv), (i), (ii)
b. (iv), (iii), (i), (ii)
c. (iii), (iv), (ii), (i)
d. (iv), (iii), (ii), (i)

Linked Items

[Read the passage below and answer the questions that follow based on your understanding of the passage]
Cathode ray oscilloscope is an electronic device which gives a visual representation of electrical quantities such as voltage and current waveforms in an electrical circuit. The name cathode ray is given because the electron beam was first thought to consists of rays from the cathode. A CRO consists of the Cathode Ray Tube (CRT), power supplies, time base circuit and deflection voltage amplifiers. The heart of cathode ray oscilloscope is CRT. Its chief advantage is that it produces the visual representation directly with extremely high speed because of the high velocity of electrons.

46. The oscilloscope can be considered as a :
a. low impedance instrument
b. high impedance instrument
c. medium impedance instrument
d. infinite impedance instrument

47. Sawtooth waves are used most frequently to move the electron beam in an oscilloscope :
a. back and forth across the screen
b. up and down on the screen
c. back and down on the screen
d. none of the above

48. The deflection sensitivity of a CRT depends inversely on the :
a. length of the vertical deflecting plates
b. distance between screen and deflecting plates
c. deflecting voltage
d. separation between Y plates

49. Two complete signal cycles would be displaced on the screen scope when time period of the sweep generator is __________ the signal time period.
a. half
b. twice
c. equal
d. thrice

50. An electrostatic cathode ray oscilloscope is a :
a. current indicating device
b. voltage indicating device
c. Both (A) and (B) above
d. None of the above

Score =

Correct Answer: