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BSNL GE-JTO Recruitment Examination
1. Reactive current through the capacitive load produces
a) Magnetic field b) Electric field c) Supermagnetic field d) None
2. One of the following which gives piero-electric effect is
a) Mu metal b) PVDF c) Sapphire d) Ferrites
3. PZT piezo- electric materials have
a) Higher curie temperature b) Lower curie temperature
c) Absolute temperature d) None
4. The residual resistivity of a binary alloy at OK is
a) The sum of the residual resistivities of the component metals
b) The difference of the residual resistivities of the component metals.
c) The product of the residual resistivities of the component metals
d) Dependent on the concentration of the minor component in the alloy
5. In active filter circuits, inductances are avoided mainly because they
a) Are always associated with some resistance
b) Are bulky and unsuitable for miniaturisation
c) Are non-linear in nature
d) Saturate quickly
6. The depletion layer across a p-n junction lies
a) mostly in the p-region b) mostly in the n-region
c) equally to both p and n region d) entirely in the p-region
7. The voltage induced in a loop of wire rotating in a strong and steady magnetic field is
a) pulsating dc b) dc c) rectified ac d) ac
8. One of the following types of capacitor which is polarized is
a) Electrolytic b) Ceramic c) Paper d) Mylar
9. Electric shock is
a) Always fatal b) Never fatal c) Sometimes fatal d) Always disfiguring
10. A typical value of filter capacitor for 50 Hz ripple is
a) 16mF b) 10F c) 10mF d) None
11. A telephone relay armature is made of material with
a) High electrical conductivity b) Low electrical conductivity
c) Negligible conductivity d) None
12. Larger the value of filter capacitor
a) Larger is the peak-peak value of ripple voltage
b) Larger is the peak current in the rectifying diode
c) Longer is the time that current pulse flows through the diode
d) Smaller is the dc voltage across the load
13. Barrier potential in a P-N junction is caused by
a) Thermally generated electrons and holes
b) Diffusion of majority carriers across the junction
c) Migration of minority carriers across the junction
d) Flow of drift current
14. The polarity of VGS for E-only MOSFET is
a) positive b) negative c) zero d) depends on P or N channel
15. The following which will serve as a donor impurity in silicon
a) Boron b) Indium c) Germanium d) Antimony
16. When bias applied to a vari-cap diode is increased, its capacitance
a) is decreased b) is increased c) remains constant d) first increases and then decreases.
17. In case of a bipolar transistor a is
a) positive and greater than 1 b) positive and less than 1
c) negative and greater than 1 d) negative and less than 1
18. A BJT is
a) not very sensitive to radiations
b) very sensitive to radiations
c) independent of radiations
d) none
19. An SCR may be considered to be
a) 2 diodes b) 3 diodes c) 4 diodes d) 5 diodes
20. For a BJT, under the saturation condition
a) IC = bIB b) IC > bIB
c) IC is independent of all other parameters
d) IC < bIB
21. In modern MOSFET’s the material used for the gate is
a) High purity silicon b) High purity silica
c) Heavily doped polycrystalline silicon d) Epitaxial grown silicon
22. Find the Norton\'s equivalent of the circuit given below
Ans. d
23. When the source in the circuit shown is a sinusoidal source then the input voltage is
a) 10V b) 5V c) 27V d) 24V
24. The time constant of the network shown in the given figure is given by
Ans. a
25. The voltage transfer ratio of two-port networks connected in cascade may be conveniently obtained from the
a) product of the individual ABCD matrices of the two networks
b) product of voltage transfer ratios of the two individual networks
c) sum of the Z- matrices of the two networks
d) sum of the h – matrices of the two networks
26. When a network has response with time as shown in fig. then which one of the following diagrams represents the location of the poles of this network ?
Ans. d
27. For the network shown in the given fig. the ratio is
a) 1/3 b) 2/3 c) 3/4 d) 4/3
28. An attenuator drops a 10V signal to 50mv in an experiment. The loss in decibels is
a) –40dB b) –6dB c) –55dB d) –60dB
29. When the network has 10 nodes and 17 branches then the number of different node pair voltages would be
a) 7 b) 9 c) 10 d) 45
30. The circuit shown in the following fig. will act as an ideal current source with respect to terminals A and B when frequency is
a) zero b) 1rad/s c) 4rad/s d) 16rad/s
31. When a short vertical grounded antenna is required to radiate at 1MHz and the effective height of the antenna is 30 m then the calculated value of the radiation resistance is
a) 1.58 W b) 158 W c) 15.8 W d) None of these
32. Shannon’s law relates
a) antenna gain to bandwidth
b) frequency to antenna gain
c) antenna gain to transmission losses
d) information carrying capacity to S/N ratio
33. One of the following modes which has the characteristic of attenceation becoming less as the frequency is increased and is attractive at microwave frequencies of circular cylindrical wave guides is
a) TE1 mode b) TM01 mode c) TE01 mode d) Higher order mode
34. For a transmission line, the propogation constant, for a TEM wave travelling in it is given by (Where the symbols have the usual meanings )
a) [(R+jwL) (G+jwc)]
b) [R+jwL) (G+jwc)] ½
c) [ (R-jwL) (G + jwc) ] ½
d) [(R-jwL) ( G+jw2c)]1/3
35. The advantages of wave guides over co-axial lines would include which of the following features-
1. Easier to use 2. lower power losses
3. Higher operating frequencies possible
a) 1 and 2 b) 1 and 3 c) 2 and 3 d) 1,2 and 3
36. When a 75 ohm transmission line is to be terminated in two resistive loads R1 and R2 such that the standing pattern in the two cases have the same SWR, then the values of R1 and R2 (in ohms) should be
a) 250 and 200 respectively b) 225 and 25 respectively
c) 100 and 150 respectively d) 50 and 125 respectively
37. The degenerate modes in a wave guide are characterized by
a) Same cut off frequencies but different field distribution
b) Same cut off frequencies and same field distributions
c) Different cut off frequencies but same field distributions
d) Different cut off frequencies and different field distributions
38. A TEM wave impinges obliquely on a dielectric-dielectric boundary with Er1=2 and Er2=1, the angle of incidence for total reflection is
a) 30o b) 60o c) 45o d) 90o
39. The radiation pattern of Hertzian dipole in the plane perpendicular to the dipole is a
a) Null b) Circle c) Figure of eight d) None of the above
40. Permeance is the
a) square of reluctance b) reluctance c) reciprocal of the reluctance d) cube of the reluctance.
41. One of the following which is an active transducer is
a) Photoelectric b) Photovoltaic c) Photo-conductive d) Photo emission
42. The wein bridge uses only
a) Inductors b) Capacitors c) Resistors d) Capacitors and Resistors
43. The greater the value of Q
a) higher will be the bandwidth of the resonant circuit.
b) smaller will be the bandwidth of the resonant circuit.
c) nothing can be said
d) none.
44. The most serious source of error in a) c) bridge measurement is
a) eddy currents b) leakage currents c) residual imperfectness d) stray fields
45. Moving iron instruments
a) have a linear scale b) do not have a linear scale c) both a and b d) none
46. If accuracy is the main consideration, which one of the following voltmeters should one select
a) 100 v ; 2 mA
b) 100 v ; 100 ohm/volt
c) 100 v ; 1mA
d) 10,000 v ; 10 mA
47. In dc tacho generators used for measurement of speed of a shaft, frequent calibration has to be done because
a) the contacts wear off
b) the strength of permanent magnet decreases with age
c) the armature current produces heating effect
d) there is back emf.
48. Ideal transformer cannot be described by
a) h parameters b) ABCD parameters c) G parameters d) parameters
49. Consider the following statements
A3- phase balanced supply system is connected to a 3 phase unbalanced load) Power supplied to this load can be measured using
1. Two wattmeters
2. One wattmeter
3. Three wattmeters
Which of these statements is/are correct?
a) 1 and 2 b) 1 and 3 c) 2 and 3 d) 3 alone
50. The function of the reference electrode in a pH meter is to
a) Produce a constant voltage
b) Provide temperature compensation
c) Provide a constant current
d) Measure average pH value
51. Match the column A (Devices) with column B (Characteristics) and select the correct answer by using the codes given below the column
Column A Column B
A) BJT 1. Voltage controlled negative resistance
B) MOSFET 2. High current gain
C) Tunnel diode 3. Voltage regulation
D) Zener diode 4. High input impedance
Codes :
A B C D
a) 1 4 2 3
b) 2 4 1 3
c) 2 3 1 4
d) 1 3 2 4
52. A thyristor during forward blocking state is associated with
a) large current, low voltage.
b) low current, large voltage.
c) medium current, large voltage
d) low current, medium voltage.
53. In controlled rectifiers, the nature of load current i.e. whether load current is continuous or discontinuous
a) does not depend on type of load and firing angle delay
b) depends both on the type of load and firing angle delay
c) depends only on the type of load)
d) depends only on the firing angle delay.
54. A single phase voltage controller feeds power to a resistance of 10 W. The source voltage is 200 V rms. For a firing angle of 900, the rms value of thyristor current in amperes is
a) 20 b) 15 c) 10 d) 5
55. In the performance of single phase and three phase full converters the effect of source inductance is to
a) reduce the ripples in the load current
b) make discontinuous current as continuous
c) reduce the output voltage
d) increase the load voltage.
56. The cycloconverters (CCs) require natural or forced commutation as under
a) natural commutation in both step up and step down CCs
b) forced commutation in both step up and step down CCs
c) forced commutation in step up CCs
d) forced commutation in step down CCs
57. Power transistors are more commonly of
a) silicon npn type b) silicon pnp type c) silicon nnp type d) silicon npp type
58. C is a
a) Middle level language b) High level language c) Low level language d) None of above
59. What will be output of program
main ( )
{ int i ;
print f ("Enter value of i");
scant ("%d", & i);
if ( i = 5 )
print f ("you entered 5");
else
print f ("you entered %d", i ); }
if user entered 100 then
a) 5 b) 100 c) 1005 d) None
60. (7F)16 + (BA)16 = (?)16
a) 481 b) 139 c) –481 d) –139
BSNL GE-JTO Recruitment Examination
1. Reactive current through the capacitive load produces
a) Magnetic field b) Electric field c) Supermagnetic field d) None
2. One of the following which gives piero-electric effect is
a) Mu metal b) PVDF c) Sapphire d) Ferrites
3. PZT piezo- electric materials have
a) Higher curie temperature b) Lower curie temperature
c) Absolute temperature d) None
4. The residual resistivity of a binary alloy at OK is
a) The sum of the residual resistivities of the component metals
b) The difference of the residual resistivities of the component metals.
c) The product of the residual resistivities of the component metals
d) Dependent on the concentration of the minor component in the alloy
5. In active filter circuits, inductances are avoided mainly because they
a) Are always associated with some resistance
b) Are bulky and unsuitable for miniaturisation
c) Are non-linear in nature
d) Saturate quickly
6. The depletion layer across a p-n junction lies
a) mostly in the p-region b) mostly in the n-region
c) equally to both p and n region d) entirely in the p-region
7. The voltage induced in a loop of wire rotating in a strong and steady magnetic field is
a) pulsating dc b) dc c) rectified ac d) ac
8. One of the following types of capacitor which is polarized is
a) Electrolytic b) Ceramic c) Paper d) Mylar
9. Electric shock is
a) Always fatal b) Never fatal c) Sometimes fatal d) Always disfiguring
10. A typical value of filter capacitor for 50 Hz ripple is
a) 16mF b) 10F c) 10mF d) None
11. A telephone relay armature is made of material with
a) High electrical conductivity b) Low electrical conductivity
c) Negligible conductivity d) None
12. Larger the value of filter capacitor
a) Larger is the peak-peak value of ripple voltage
b) Larger is the peak current in the rectifying diode
c) Longer is the time that current pulse flows through the diode
d) Smaller is the dc voltage across the load
13. Barrier potential in a P-N junction is caused by
a) Thermally generated electrons and holes
b) Diffusion of majority carriers across the junction
c) Migration of minority carriers across the junction
d) Flow of drift current
14. The polarity of VGS for E-only MOSFET is
a) positive b) negative c) zero d) depends on P or N channel
15. The following which will serve as a donor impurity in silicon
a) Boron b) Indium c) Germanium d) Antimony
16. When bias applied to a vari-cap diode is increased, its capacitance
a) is decreased b) is increased c) remains constant d) first increases and then decreases.
17. In case of a bipolar transistor a is
a) positive and greater than 1 b) positive and less than 1
c) negative and greater than 1 d) negative and less than 1
18. A BJT is
a) not very sensitive to radiations
b) very sensitive to radiations
c) independent of radiations
d) none
19. An SCR may be considered to be
a) 2 diodes b) 3 diodes c) 4 diodes d) 5 diodes
20. For a BJT, under the saturation condition
a) IC = bIB b) IC > bIB
c) IC is independent of all other parameters
d) IC < bIB
21. In modern MOSFET’s the material used for the gate is
a) High purity silicon b) High purity silica
c) Heavily doped polycrystalline silicon d) Epitaxial grown silicon
22. Find the Norton\'s equivalent of the circuit given below
Ans. d
23. When the source in the circuit shown is a sinusoidal source then the input voltage is
a) 10V b) 5V c) 27V d) 24V
24. The time constant of the network shown in the given figure is given by
Ans. a
25. The voltage transfer ratio of two-port networks connected in cascade may be conveniently obtained from the
a) product of the individual ABCD matrices of the two networks
b) product of voltage transfer ratios of the two individual networks
c) sum of the Z- matrices of the two networks
d) sum of the h – matrices of the two networks
26. When a network has response with time as shown in fig. then which one of the following diagrams represents the location of the poles of this network ?
Ans. d
27. For the network shown in the given fig. the ratio is
a) 1/3 b) 2/3 c) 3/4 d) 4/3
28. An attenuator drops a 10V signal to 50mv in an experiment. The loss in decibels is
a) –40dB b) –6dB c) –55dB d) –60dB
29. When the network has 10 nodes and 17 branches then the number of different node pair voltages would be
a) 7 b) 9 c) 10 d) 45
30. The circuit shown in the following fig. will act as an ideal current source with respect to terminals A and B when frequency is
a) zero b) 1rad/s c) 4rad/s d) 16rad/s
31. When a short vertical grounded antenna is required to radiate at 1MHz and the effective height of the antenna is 30 m then the calculated value of the radiation resistance is
a) 1.58 W b) 158 W c) 15.8 W d) None of these
32. Shannon’s law relates
a) antenna gain to bandwidth
b) frequency to antenna gain
c) antenna gain to transmission losses
d) information carrying capacity to S/N ratio
33. One of the following modes which has the characteristic of attenceation becoming less as the frequency is increased and is attractive at microwave frequencies of circular cylindrical wave guides is
a) TE1 mode b) TM01 mode c) TE01 mode d) Higher order mode
34. For a transmission line, the propogation constant, for a TEM wave travelling in it is given by (Where the symbols have the usual meanings )
a) [(R+jwL) (G+jwc)]
b) [R+jwL) (G+jwc)] ½
c) [ (R-jwL) (G + jwc) ] ½
d) [(R-jwL) ( G+jw2c)]1/3
35. The advantages of wave guides over co-axial lines would include which of the following features-
1. Easier to use 2. lower power losses
3. Higher operating frequencies possible
a) 1 and 2 b) 1 and 3 c) 2 and 3 d) 1,2 and 3
36. When a 75 ohm transmission line is to be terminated in two resistive loads R1 and R2 such that the standing pattern in the two cases have the same SWR, then the values of R1 and R2 (in ohms) should be
a) 250 and 200 respectively b) 225 and 25 respectively
c) 100 and 150 respectively d) 50 and 125 respectively
37. The degenerate modes in a wave guide are characterized by
a) Same cut off frequencies but different field distribution
b) Same cut off frequencies and same field distributions
c) Different cut off frequencies but same field distributions
d) Different cut off frequencies and different field distributions
38. A TEM wave impinges obliquely on a dielectric-dielectric boundary with Er1=2 and Er2=1, the angle of incidence for total reflection is
a) 30o b) 60o c) 45o d) 90o
39. The radiation pattern of Hertzian dipole in the plane perpendicular to the dipole is a
a) Null b) Circle c) Figure of eight d) None of the above
40. Permeance is the
a) square of reluctance b) reluctance c) reciprocal of the reluctance d) cube of the reluctance.
41. One of the following which is an active transducer is
a) Photoelectric b) Photovoltaic c) Photo-conductive d) Photo emission
42. The wein bridge uses only
a) Inductors b) Capacitors c) Resistors d) Capacitors and Resistors
43. The greater the value of Q
a) higher will be the bandwidth of the resonant circuit.
b) smaller will be the bandwidth of the resonant circuit.
c) nothing can be said
d) none.
44. The most serious source of error in a) c) bridge measurement is
a) eddy currents b) leakage currents c) residual imperfectness d) stray fields
45. Moving iron instruments
a) have a linear scale b) do not have a linear scale c) both a and b d) none
46. If accuracy is the main consideration, which one of the following voltmeters should one select
a) 100 v ; 2 mA
b) 100 v ; 100 ohm/volt
c) 100 v ; 1mA
d) 10,000 v ; 10 mA
47. In dc tacho generators used for measurement of speed of a shaft, frequent calibration has to be done because
a) the contacts wear off
b) the strength of permanent magnet decreases with age
c) the armature current produces heating effect
d) there is back emf.
48. Ideal transformer cannot be described by
a) h parameters b) ABCD parameters c) G parameters d) parameters
49. Consider the following statements
A3- phase balanced supply system is connected to a 3 phase unbalanced load) Power supplied to this load can be measured using
1. Two wattmeters
2. One wattmeter
3. Three wattmeters
Which of these statements is/are correct?
a) 1 and 2 b) 1 and 3 c) 2 and 3 d) 3 alone
50. The function of the reference electrode in a pH meter is to
a) Produce a constant voltage
b) Provide temperature compensation
c) Provide a constant current
d) Measure average pH value
51. Match the column A (Devices) with column B (Characteristics) and select the correct answer by using the codes given below the column
Column A Column B
A) BJT 1. Voltage controlled negative resistance
B) MOSFET 2. High current gain
C) Tunnel diode 3. Voltage regulation
D) Zener diode 4. High input impedance
Codes :
A B C D
a) 1 4 2 3
b) 2 4 1 3
c) 2 3 1 4
d) 1 3 2 4
52. A thyristor during forward blocking state is associated with
a) large current, low voltage.
b) low current, large voltage.
c) medium current, large voltage
d) low current, medium voltage.
53. In controlled rectifiers, the nature of load current i.e. whether load current is continuous or discontinuous
a) does not depend on type of load and firing angle delay
b) depends both on the type of load and firing angle delay
c) depends only on the type of load)
d) depends only on the firing angle delay.
54. A single phase voltage controller feeds power to a resistance of 10 W. The source voltage is 200 V rms. For a firing angle of 900, the rms value of thyristor current in amperes is
a) 20 b) 15 c) 10 d) 5
55. In the performance of single phase and three phase full converters the effect of source inductance is to
a) reduce the ripples in the load current
b) make discontinuous current as continuous
c) reduce the output voltage
d) increase the load voltage.
56. The cycloconverters (CCs) require natural or forced commutation as under
a) natural commutation in both step up and step down CCs
b) forced commutation in both step up and step down CCs
c) forced commutation in step up CCs
d) forced commutation in step down CCs
57. Power transistors are more commonly of
a) silicon npn type b) silicon pnp type c) silicon nnp type d) silicon npp type
58. C is a
a) Middle level language b) High level language c) Low level language d) None of above
59. What will be output of program
main ( )
{ int i ;
print f ("Enter value of i");
scant ("%d", & i);
if ( i = 5 )
print f ("you entered 5");
else
print f ("you entered %d", i ); }
if user entered 100 then
a) 5 b) 100 c) 1005 d) None
60. (7F)16 + (BA)16 = (?)16
a) 481 b) 139 c) –481 d) –139
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