Question Bank
VSSC Scientist Engineer Exam (Electrical) - English
Duration: 60 · Questions: 50 · Max Marks: 50 · Language: 3
Electrical Engineering
1
Assuming both the voltage sources are in phase, the value of R for which maximum power is transferred from circuit A to circuit B is
2
For the intrinsic gallium-arsenide, the conductivity at room temperature 25°C is 10-6 (ohm-m)-1, the electron and hole nobilities are 0.85 m2/V-s and 0.04 m2/V-s respectively. What is the intrinsic carrier concentration at the room temperature?
3
The resistivity of intrinsic germanium at 30°C is 0.46 –m. What is the intrinsic carrier density at 30°C if the electron mobility is 0.38 m2/V-s and the hole mobility is 0.18 m2/V-s?
4
Heat conduction in a semiconductor takes place
5
Brewster angle is the angle when a wave is incident on the surface of a perfect dielectric at which there is no reflected wave and the incident wave is
6
An electrical breakdown of a p-n junction occurs if
7
The chief deterrent to the widespread application of superconducting materials is
8
Which one of the following properties is not observed in the carbon nanotubes ?
9
The evidence for the importance of electron-phonon interaction in super-conductors comes from
10
Which one of the following materials is used for cable insulation ?
11
For high speed reading and storing of information in a computer, the material used is
12
The temperature above which an anti-ferromagnetic material becomes paramagnetic is called
13
Which effect is the converse of Peltier effect ?
14
Magnetic materials which may be readily magnetized in either direction are
15
Consider the following statements regarding a ferromagnetic material:
1.Below the ferromagnetic Curie temperature, the ferromagnetic materials exhibit hysteresis effect.
2.The coercive force is the filed required to reduce the flux density to zero.
Which of the above statements is/are correct?
1.Below the ferromagnetic Curie temperature, the ferromagnetic materials exhibit hysteresis effect.
2.The coercive force is the filed required to reduce the flux density to zero.
Which of the above statements is/are correct?
16
The impact ionization phenomenon in semiconductor may be viewed as the reverse process of
17
Refractive index of a slice glass can be reduced by doping it with tiny amount of
18
If a diameter of a copper wire is increased by two times keeping its terminal voltage same, then the drift velocity will
19
In an induction type energy meter, the steady speed attained by the rotating disc is
1.Proportional to the deflecting torque.
2.Proportional to the resistance of the path of eddy currents.
3.Inversely proportional to the effective readings of disc from its axis.
4.Inversely proportional to the square of brake magnetic flux.
Which of the above are correct?
1.Proportional to the deflecting torque.
2.Proportional to the resistance of the path of eddy currents.
3.Inversely proportional to the effective readings of disc from its axis.
4.Inversely proportional to the square of brake magnetic flux.
Which of the above are correct?
20
If ‘KCLFTSB’ stands for ‘best of luck’ and ‘SHSWDG’ stands for ‘good wishes’, which of the following indicates ‘ace the exam’?
21
Consider the following statements associated with the basic electrostatic properties of ideal conductors:
1.The resultant field inside is zero.
2.The net charge density in the interior is zero.
3.Any net charges reside on the surface.
4.The surface is always equipotential.
5.The field just outside is zero.
Which of the above statements are correct?
1.The resultant field inside is zero.
2.The net charge density in the interior is zero.
3.Any net charges reside on the surface.
4.The surface is always equipotential.
5.The field just outside is zero.
Which of the above statements are correct?
22
A semiconductor device made out of a material having very high temperature coefficient of resistance is
23
The electrical conductivity of a semiconductor increases with increase in temperature because
24
Which of the following are associated with soft superconductors?
1.Silsbee’s rule
2.Meissner effect
3.Faraday rotation
4.Curie-Weiss law
1.Silsbee’s rule
2.Meissner effect
3.Faraday rotation
4.Curie-Weiss law
25
In a two-channel oscilloscope operating in x-y mode, two in-phase 50 Hz sinusoidal waveforms of equal amplitude are fed to the two channels. What will be the resultant pattern on the screen?
26
Materials, whose resistivity at very low temperature plunges from a finite value to zero and remains there upon further cooling, are known as
27
In a superconductor, is the temperature is decreased below its critical temperature, the value of critical magnetic field will
28
The imaginary part of dielectric constant determines
29
Direction: Each of the items consists of two statements, one labeled as the ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answers to these items using the codes given below
30
In 8085A microprocessor, the operation performed by the instruction LHLD 2100 H is
31
If the magnetic susceptibility of a specimen is small and positive, the specimen is
32
Manganese ferrite is a 1 : 1 mixture of
33
When a ferromagnetic substance is magnetized, small changes in dimensions occur. Such a phenomenon is known as
34
In ferromagnetic , anti-ferromagnetic and ferromagnetic materials, the atomic thermal motions counteract the coupling forces between the adjacent atomic dipole moments, thereby causing
35
The Hall effect voltage in intrinsic silicon
36
Most outstanding property of indium antimonide is
37
Which of the following semiconducting compounds is used in photoconductive devices?
38
Consider the following transducers:
1.LVDT
2.Piezoelectric
3.Thermocouple
4.Photovoltaic cell
Which of the above are active transducers?
1.LVDT
2.Piezoelectric
3.Thermocouple
4.Photovoltaic cell
Which of the above are active transducers?
39
Consider the following statements regarding magnetic materials:
1.A diamagnetic material has no permanent dipole
2.Paramagnetic material has anti-parallel orientation of equal moments with neighboring dipoles
3.Ferrimagnetic material has anti parallel orientation of unequal moments between neighboring dipoles
4.Anti-ferromagnetic material has negligible interaction between neighboring dipoles
Which of these statements are correct?
1.A diamagnetic material has no permanent dipole
2.Paramagnetic material has anti-parallel orientation of equal moments with neighboring dipoles
3.Ferrimagnetic material has anti parallel orientation of unequal moments between neighboring dipoles
4.Anti-ferromagnetic material has negligible interaction between neighboring dipoles
Which of these statements are correct?
40
Consider the following statements regarding hysteresis loops of hard and soft magnetic materials:
1.Hysteresis loss of hard magnetic material will be less than that of soft material
2.Coercivity of hard materials will be greater than that of soft material
3.Retentivity of the two materials will always be equal
Which of these statements are correct?
1.Hysteresis loss of hard magnetic material will be less than that of soft material
2.Coercivity of hard materials will be greater than that of soft material
3.Retentivity of the two materials will always be equal
Which of these statements are correct?
41
Loss-tangent in plane waves in lossy dielectrics will be
42
Orientational polarization is
43
Behavior of conductors, semiconductors and insulators is explained on the basis of
44
In general, for a superconductor, which of the following statements is true?
45
Ferro-electric materials have a
46
In the magnetic core the electromotive forces (emf) induced in accordance with Faraday’s law of electromagnetic induction give rise to
47
Consider the following characterizing parameters of a material:
1.Magnetic permeability
2.Electron relaxation time
3.Electron effective mass
4.Energy band gap
In case of metals, increase in one of the above parameter decreases its conductivity, while increase in another increases the conductivity. There are respectively
1.Magnetic permeability
2.Electron relaxation time
3.Electron effective mass
4.Energy band gap
In case of metals, increase in one of the above parameter decreases its conductivity, while increase in another increases the conductivity. There are respectively
48
Some magnetic materials may be classified on the basis of
1.Susceptibility
2.Saturation
3.Spin arrangement
4.Nature of hysteresis loop
5.Domain structure
6.Critical temperature above which it behaves as a paramagnetic material
Which of these can be used to distinguish between ferri and ferromagnetic materials?
1.Susceptibility
2.Saturation
3.Spin arrangement
4.Nature of hysteresis loop
5.Domain structure
6.Critical temperature above which it behaves as a paramagnetic material
Which of these can be used to distinguish between ferri and ferromagnetic materials?
49
Magnetism is mainly due to only electron spin around their axis in case of
50
For Paramagnetic materials, the relative permeability is