Electric Traction Multiple Choice Questions and Answers pdf free download | Electrical Engineering Questions

1.    Which of the following is an advantage of electric traction over other methods of traction ?
2.    Which of the following is the voltage for single phase A.C. system ?
3.    Long distance railways use which of the following ?
4.    The speed of a locomotive is controlled by ______.
5.    Main traction systems used in India are, those using
6.    In India diesel locomotives are manufactured at
7.    For diesel locomotives the range of horsepower is
8.    _______ locomotive has the highest operational availability.
9.    The horsepower of steam locomotives is _______.
10.   The overall efficiency of steam locomotive is around
11.   In tramways which of the following motors is used ?
12.   In a steam locomotive electric power is provided through
13.   Which of the following drives is suitable for mines where explosive gas exists ?
14.   In case of locomotives the tractive power is provided by
15.   Overload capacity of diesel engines is usually restricted to
16.   In case of steam engines the steam pressure is
17.   The steam engine provided on steam locomotives is
18.   Electric locomotives in India are manufactured at
19.   The wheels of a train, engine as well as bogies, are slightly tapered to
20.   Automatic signalling is used for which of the following trains ?
21.   The efficiency of diesel locomotives is nearly
22.   The speed of a superfast train is _______.
23.   The number of passanger coaches that can be attached to a diesel engine locomotive on broad gauge is usually restricted to
24.   Which of the following state capitals is not on broad gauge track ?
25.   Which of the following is the advantage of electric braking ?
26.   Which of the following braking systems on the locomotives is costly ?
27.   Tractive effort is required to _______.
28.   For given maximum axle load tractive efforts of AC. locomotive will be
29.   Co-efficient of adhesion reduces due to the presence of which of the following ?
30.    Due to which of the following co-efficient of adhesion improves ?
31.    Quadrilateral speed-time curve pertains to which of the following services ?
32.    Which of the following is the disadvantage of electric traction over other systems of traction ?
33.    Co-efficient of adhesion is ______.
34.    Speed-time curve of main line service differs from those of urban and suburban services on following account
35.    The rate of acceleration on suburban or urban services is restricted by the consideration of
36.    The specific energy consumption of a train depends on which of the following ?
37.    The friction at the track is proportional to _______.
38.    The air resistance to the movement of the train is proportional to
39.    The normal value of adhesion friction is
40.    The pulsating torque exerted by steam locomotives causes which of the following?
41.    Which of the following braking systems is used on steam locomotives ?
42.    Vacuum is created by which of the following?
43.    The resistance encountered by a trainin motion is on account of
44.    Battery operated trucks are used in
45     method can bring the locomotive to dead stop.
46.    The value of co-efficient of adhesion will be high when rails are
47.    The voltage used for suburban trains in D.C. system is usually
48.    For three-phase induction motors which of the following is the least efficient method of speed control ?
49.    Specific energy consumption becomes
50.    In main line service as compared to urban and suburban service
51.    Locomotive having monomotor bogies
52.    Series motor is not suited for traction duty due to which of the following account ?
53.    When a bogie negotiates a curve, reduction in adhesion occurs resulting in sliding. Thus sliding is acute when
54.    Energy consumption in propelling the train is required for which of the following?
55.    An ideal traction system should have
56     ______ have maximum unbalanced forces.
57.    Specific energy consumption is affected by which of the following factors ?
58.    In case of ________ free running and coasting periods are generally long.
59.    Overhead lines for power supply to tramcars are at a minimum height of
60.    The return circuit for tramcars is through    
61.    Specific energy consumption is least in _______ service.
62.    Locomotives with monometer bogies have _____.
63     _______ was the first city in India to adopt electric traction.
64     _______ frequency is not common in low frequency traction system
65.    For 25 kV single phase system power supply frequency is   
66.    Power for lighting in passanger coach, in a long distance electric train, is provided
67.    In India, electrification of railway track was done for the first time in which of the following years ?
68.    Suri transmission is _______.
69.    In case of a steam engine an average coal consumption per km is nearly
70.    Which of the following happens in Kando system ?
71.    For which of the following locomotives the maintenance requirements are the least?
72.    Which of the following methods is used to control speed of 25 kV, 50 Hz single phase traction ?
73.    If the co-efficient of adhesion on dry rails is 0.26, which of the following could be the value for wet rails ?
74    watt-hours per tonne km is usually the specific energy consumption for suburban services.
75.    The braking retardation is usually in the range
76.    The rate of acceleration on suburban or urban service is in the range
77.    The coasting retardation is around ______.

Control Systems Multiple Choice Questions and Answers pdf free download | Electrical Engineering Questions

1.    In an open loop control system ______.
2.    For open control system which of the following statements is incorrect ?
3.    A control system in which the control action is somehow dependent on the output is known as
4.    In closed loop control system, with positive value of feedback gain the overall gain of the system will
5.    Which of the following is an open loop control system ?
6.    Which of the following statements is not necessarily correct for open control system ?
7.    In open loop system ______.
8     ______ has tendency to oscillate.
9.    A good control system has all the following features except
10.    A car is trying at a constant speed of 50 km/h, which of the following is the feedback element for the driver ?
11.    The initial response when the output is not equal to input is called
12.    A control system working under unknown random actions is called   
13.    An automatic toaster is a ______ loop control system.
14.    Any externally introduced signal affecting the controlled output is called a
15.    A closed loop system is distinguished from open loop system by which of the following ?
16      ______ is a part of the human temperature control system.
17.     By which of the following the control action is determined when a man walks along a path ?
18     _______ is a closed loop system.
19.    Which of the following devices are commonly used as error detectors in instruments ?
20.    Which of the following should be done to make an unstable system stable ?
21      _______ increases the steady state accuracy.
22.     A.C. servomotor resembles ______.
23.    As a result of introduction of negative feedback which of the following will not decrease ?
24.    Regenerative feedback implies feedback with ______.
25.    The output of a feedback control system must be a function of
26      _____ is an open loop control system.
27.    A control system with excessive noise, is likely to suffer from
28.    Zero initial condition for a system means
29.    Transfer function of a system is used to calculate which of the following ?
30.    The band width, in a feedback amplifier.
31.    On which of the following factors does the sensitivity of a closed loop system to gain changes and load disturbances depend ?
32.    The transient response, with feedback system,
33.    The second derivative input signals modify which of the following ?
34.    Which of the following statements is correct for any closed loop system ?
35.    Which of the following statements is correct for a system with gain margin close to unity or a phase margin close to zero ?
36.    Due to which of the following reasons excessive bond width in control systems should be avoided ?
37.    In a stable control system backlash can cause which of the following ?
38.    In an automatic control system which of the following elements is not used ?
39.    In a control system the output of the controller is given to
40.    A controller, essentially, is a ______.
41.    Which of the following is the input to a controller ?
42.    The on-off controller is a _____ system.
43.    The capacitance, in force-current analogy, is analogous to
44.    The temperature, under thermal and electrical system analogy, is considered analogous to
45.    In electrical-pneumatic system analogy the current is considered analogous to
46.    In liquid level and electrical system analogy, voltage is considered analogous to
47.    The viscous friction co-efficient, in force-voltage analogy, is analogous to
48.    In force-voltage analogy, velocity is analogous to
49.    In thermal-electrical analogy charge is considered analogous to
50.    Mass, in force-voltage analogy, is analogous to _____.
51.    The transient response of a system is mainly due to
52     signal will become zero when the feedback signal and reference signs are equal.
53.    A signal other than the reference input that tends to affect the value of controlled variable is known as   
54.    The transfer function is applicable to which of the following ?
55.    From which of the following transfer function can be obtained ?
56     _______ is the reference input minus the primary feedback.
57.    The term backlash is associated with ______.
58.    With feedback _____ increases.
59.    By which of the following the system response can be tested better ?
60.    In a system zero initial condition means that
61.    In a system low friction co-efficient facilitates
62.    Hydraulic torque transmission system is analog of
63.    Spring constant in force-voltage analogy is analogous to
64.    The frequency and time domain are related through which of the following?
65.    An increase in gain, in most systems, leads to _______.
66.    Static error co-efficients are used as a measure of the effectiveness of closed loop systems for specified     ________ input signal.
67.    A conditionally stable system exhibits poor stability at
68.    The type 0 system has ______ at the origin.
69.    The type 1 system has ______ at the origin.
70.    The type 2 system has _______ at the origin.
71.    The position and velocity errors of a type-2 system are
72.    Velocity error constant of a system is measured when the input to the system is unit _______ function.
73.    In case of type-1 system steady state acceleration is
74.    If a step function is applied to the input of a system and the output remains below a certain level for all the time, the system is
75.    Which of the following is the best method for determining the stability and transient response ?
76.    Phase margin of a system is used to specify which of the following ?
77.    Addition of zeros in transfer function causes which of the following ?
78.    technique is not applicable to nonlinear system ?
79.    In order to increase the damping of a badly underdamped system which of following compensators may be used ?
80.    The phase lag produced by transportation relays
81.    In a stable control system saturation can cause which of the following ?
82.    Which of the following can be measured by the use of a tacho generator ?
83      ______ is not a final control element.
84.    Which of the following is the definition of proportional band of a controller ?
85.    In pneumatic control systems the control valve used as final control element converts   
86.    Pressure error can be measured by which of the following ?
87.    Which of the following devices is used for conversion of co-ordinates ?
88.    The effect of error damping is to _______.
89     _______ technique gives quick transient and stability response
90.    A phase lag lead network introduces in the output
91.    Which of the following is the non-linearity caused by servomotor ?
92     can be extended to systems which are time-varying ?
93.    When the initial conditions of a system are specified to be zero it implies that the system is
94.    Which of the following is an electromagnetically device ?
95.    A differentiation is usually not a part of a control system because it   
96.    If the gain of the critical damped system is increased it will behave as
97.    In a control system integral error compensation _______ steady state error.
98.    With feed back _____ reduces.
99.    An amplidyne can give which of the following characteristics ?
100.  Which of the following can be measured byLVDT?

Measurement and Instrumentation Multiple Choice Questions and Answers pdf free download | Electrical Engineering Questions

1.      The use of _____ instruments is merely confined within laboratories as standardizing instruments.
2.      Which of the following instruments indicate the instantaneous value of the electrical quantity being measured at the time at which it is being measured ?
3.      _____ instruments are those which measure the total quantity of electricity delivered in a particular time.

4.    Which of the following are integrating instruments ?
5.    Resistances can be measured with the help of ________.
6     According to application, instruments are classified as
7.    Which of the following essential features is possessed by an indicating instrument ?
8.    A _____    device prevents the oscillation of the moving system and enables the latter to reach its final position quickly
9.     The spring material used in a spring control device should have the following property.
10.    Which of the following properties a damping oil must possess ?
11.    A moving-coil permanent-magnet instrument can be used as _____ by using a low resistance shunt.
12.    A moving-coil permanent-magnet instrument can be used as flux-meter
13.    Which of the following devices may be used for extending the range of instruments ?
14.    An induction meter can handle current upto _______.
15.    For handling greater currents induction wattmeters are used in conjunction with
16.    Induction type single phase energy meters measure electric energy in
17.    Most common form of A.C. meters met with in every day domestic and industrial installations are
18.    Which of the following meters are not used on D.C. circuits
19.    Which of the following is an essential part of a motor meter ?
20.    A potentiometer may be used for _______.
21     _______ is an instrument which measures the insulation resistance of an electric circuit relative to earth and one another.
22.    The household energy meter is ________.
23.    The pointer of an indicating instrument should be _______.
24.    The chemical effect of current is used in ______.
25.    In majority of instruments damping is provided by
26.    An ammeter is a ________.
27.    In a portable instrument, the controlling torque is provided by
28.    The disc of an instrument using eddy current damping should be of
29.    The switch board instruments _______.
30.    The function of shunt in an ammeter is to _______.
31.    The multiplier and the meter coil in a voltmeter are in_______.
32.    A moving iron instrument can be used for ________.
33.    The scale of a rectifier instrument is _______.
34.    For measuring current at high frequency we should use
35.    The resistance in the circuit of the moving coil of a dynamometer wattmeter should be
36.    A dynamometer wattmeter can be used for ________.
37.    An induction wattmeter can be used for _______.
38.    The pressure coil of a wattmeter should be connected on the supply side of the current coil when
39.    In a low power factor wattmeter the pressure coil is connected
40.    In a low power factor wattmeter the compensating coil is connected
41.    In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was
42.    In a 3-phase power measurement by two wattmeter method the reading of one of the wattmeter was zero. The power factor of the load must be
43.    The adjustment of position of shading bands, in an energy meter is done to provide
44.    An ohmmeter is a ________.
45.    When a capacitor was connected to the terminal of ohmmeter, the pointer indicated a low resistance initially and then slowly came to infinity position. This shows that capacitor is
46.    For measuring a very high resistance we should use ______.
47.    The electrical power to a meggar is provided by ______.
48.    In a meggar controlling torque is provided by _______.
49.    The operating voltage of a meggar is about ________.
50.    Murray loop test can be used for location of _______.
51.    Which of the following devices should be used for accurate measurement of low D.C. voltage ?
52.    It is required to measure the true open circuit e.m.f. of a battery. The best device is
53.    A voltage of about 200 V can be measured _______.
54.    A direct current can be measured by _____.
55.    To measure a resistance with the help of a potentiometer it is
56.    A phase shifting transformer is used in conjunction with
57.    Basically a potentiometer is a device for ________.
58.    In order to achieve high accuracy, the slide wire of a potentiometer should be
59.    To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that the supply for the potentiometer in taken
60.    The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a
61.    In an AC. co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be
62.    A universal RLC bridge uses ________.
63.    For measurements on high voltage capacitors, the suitable bridge is
64.    In an Anderson bridge, the unknown inductance is measured in terms of
65.    Wagner earthing device is used to eliminate errors due to
66.    For measurement of mutual inductance we can use
67.    For measurement of inductance having high value, we should use
68.    If the current in a capacitor leads the voltage by 80°, the loss angle of the capacitor is
69.    In a Schering bridge the potential of the detector above earth potential is
70.    To avoid the effect of stray magnetic field in A.C. bridges we can use
71.    If an inductance is connected in one arm of bridge and resistances in the remaining three arms
72.    A power factor meter has _______.
73.    The two pressure coils of a single phase power factor meter have
74.    In a single phase power factor meter the phase difference between the currents in the two pressure coils is
75.    In a dynamometer 3-phase power factor meter, the planes of the two moving coils are at
76.    In a vibrating reed frequency meter the natural frequencies of two adjacent reeds have a difference of
77.    In a Weston frequency meter, the magnetic axes of the two fixed coils are
78.    A Weston frequency meter is _______.
79.    A Weston synchronoscope is a ______.
80.    In a Weston synchronoscope, the fixed coils are connected across
81.    In Weston synchronoscope the moving coil is connected across
82.    The power factor of a single phase load can be calculated if the instruments available are
83.    The desirable static characteristics of a measuring system are
84.    The ratio of maximum displacement deviation to full scale deviation of the instrument is called
85.    Systematic errors are _______.
86.    Standard resistor is made from ______.
87.    Commonly used standard capacitor is ______.
88.    Operating torques in analogue instruments are ______.
89.    Commonly used instruments in power system measurement are
90.    Damping of the Ballistic galvanometer is made small to
91.    If an instrument has cramped scale for larger values, then it follows
92.    Volt box is a component to _____.
93.    E.m.f. of a Weston cell is accurately measured by
94.    The gravity controlled instrument has crowded scale because current is proportional to
95.    A sensitive galvanometer produces large deflection for a
96.    A multirang instrument has _______.
97.    The rectifier instrument is not free from _____.
98.    Alternating current is measured by ______.
99.    Most sensitive galvanometer is _______.
100.    Instrument transformers are _____.

Electrical Machine Design Materials Multiple Choice Questions and Answers pdf free download | Electrical Engineering Questions

1.   Which of the following is the major consideration to evolve a good design ?
2     ________ impose limitation on design.
3.    The efficiency of a machine should be as ______    as possible to reduce the operating cost.
4.    If an insulating material is operated beyond the maximum allowable temperature, its life is
5.    The design of mechanical parts is particularly important in case of _____ speed machines.
6.    In induction motors, the length of air gap in kept as small as mechanically possible is order to have
7.    In ______ machines, the size of the shaft is decided by the critical speed which depends on the deflection of the shaft.
8.    The length of air gap to be provided in ______ is primarily determined by power factor consideration.
9.    Electrical machines having a power output upto about 750 W may be called _______machines.
10.    Electrical machines having power outputs ranging from a few kW upto approximately 250 kW may be classified as   
11.    Commercial available medium size machines have a speed range of    ______ .
12.    The action of electromagnetic machines can be related to which ofthe following basic principles ?
13.   The change in flux linkages can be caused in which of the following ways ?
14    ______ is universally used for windings of electrical machines because it is easily workable without any possibility of fracture.
15.   Aluminium when adopted as a conductor material in ______ transformers, decreases the overall cost of the transformer
16.    Which of the following materials is used in the manufacture of resistance grids to be used in the starters of large motors ?
17.    Materials exhibiting zero value of resistivity are known as ______ .   
18.     ________ has a lowrelative permeability and is used principally in field frames when cost is of primary importance and extra weight is not objectionable.
19    ______is extensively used for those portions of magnetic circuit which carry steady flux and need superior mechanical properties ?
20.    Hot rolled sheets have ______ value of permeability.
21.    The heated parts of an electrical machine dissipate heat into their surroundings by which of the following modes of heat dissipation ?
22.    The heat dissipated by ______ from a surface depends upon its temperature and its characteristics like colour, roughness etc.
23.    The mcrease in heat dissipation by air blasts is due to increase in   
24.    On which of the following variables heat convected depends ?
25.    Which of the following methods is used for air cooling of turbo-alternators ?
26.    Multiple inlet system of air cooling of turbo-alternators can be used for machines of rating upto
27.    Which of the following is an advantage of hydrogen cooling ?
28.    The density of hydrogen is _____ times the density of air.
29.    Hydrogen has a heat transfer co-efficient _____ times that of air.
30.    The thermal conductivity of hydrogen is ______ times that of air.
31.    With conventional hydrogen cooling it is possible to increase the rating of a single unit to
32.    The noise produced by a ______ cooled machine is less as the rotor moves in a medium of smaller density.
33    cooling is the process of dissipating the armature and field winding losses to a cooling medium circulating within the winding insulation wall
34.    Machines cooled by direct cooling method may be called
35.    In direct cooled system using hydrogen both stator and rotor conductors are made
36.    With direct water cooling it is possible to have ratings of about
37.    The resistivity of water should not be less than
38.    Direct water cooling of rotor winding presents
39.    The time taken by the machine to attain 0.632 of its final steady temperature rise is called
40.    In self cooled motors the cooling time constant is about ______ than the heating time constant because cooling conditions are worse at standstill.
41.    By which of the following methods motor rating for variable load drives can be determined ?
42.    Which of the following methods does not take into account the maximum temperature rise under variable load conditions ?
43.    Which of the following methods is most accurate ?
44.    By which of the following methods the temperature rise of windings and other parts may be determined ?
45.    The slot leakage can be calculated by making which of the following assumptions ?
46.    The value of exciting or magnetizing current depends upon which of the following factors ?
47.    Tractive magnets are operated from ______.
48     electromagnets generally function as holding magnets.
49.    Which of the following is the commonly used type of electromagnets ?
50     _______ are used for construction of core of electromagnets.
51.    The design of electromagnets is based upon which of the following fundamental equations ?
52.    When the two coil sides forming a coil are spaced exactly one pole pitch apart they are said to be of ______.
53      ________ are always double layer type.
54.     The distance between the starts of two consecutive coils measured in terms of coil sides is called
55.    The winding where dummy coils are used is sometimes called
56.    Dummy coil should not be used in ______.
57.    Power transformers have rating ______.
58.    Power transformers should be designed to have maximum efficiency
59.    In transformers using hot rolled steel, the cross-section of the yoke is made about _____ greater than that of the core
60.    Yokes with rectangular cross-section are used for
61.    The cold rolled grain oriented steel has ______    permeability in the direction of the grain orientation.
62.    Cylindrical windings using circular conductors, employed in transformers, are
63.    Helical windings are used in ______.
64.    Multi-layer helical windings are commonly used in the transformers as high voltage windings
65.    Disc windings are primarily used in ______.
66.    The heat dissipating capability of transformers of ratings higher than 30 kVA in increased by providing which of the following ?
67.    Transformers with a capacity of upto _____ have a cooling radiator system with natural cooling
68.    The forced oil and air circulation method is usual one for transformers of capacities
69.    The flash point of transformer oil should be higher than
70.    The voltage control in electric supply networks in required on account of which of the following reasons ?
71.    D.C. windings are _______.
72.    The usual values of maximum flux densities for distribution transformers using hot rolled silicon steel are
73.    For 275 kV transformers, using cold rolled grain oriented steel, which of the following values of flux density may be used?
74.    For large power transformers, self oil cooled type or air blast type which of the following values of current density may be used ?
75.    A current density of _____ is ilsed for large power transformers with forced circulation of oil or with water cooling coils
76.    The high voltage winding is usually which of the following type ?
77.    Which of the following is the basic consideration in the design of insulation ?
78.    A practical formula for determining the thickness of insulation between low voltage and high voltage windings is
79.    The insulation between windings and grounded core and the insulation between the windings of the same phase is called
80.    The cylindrical windings using circular conductors are used for current rating of
81.    The surge phenomenon is particularly important in case of _______.
82.    Which of the following in an application of D.C. motors?
83.    D.C. servomotors are used in _______.
84.    The stator of a D.C. machine comprises of _______.
85.    The laminations of the armature of a D.C. machine are usually _____ thick.
86.     _______ is usually used for brush rockers
87.    ______ brushes are fragile and cause excessive wear of commutator.
88.    Which of the following brushes can be used for high values of current density ?
89     ________ is the common method of applying brushes to the commntator.
90.    Which of the following problem arises in D.C. motors which are fed from thyristor bridge circuits ?
91.    The weight of copper of both armature and field windings decreases with _____ in number of poles.
92.    In a D.C. machine the number of brush arms is _____ the number of poles.
93.    In a D.C. machine the current per brush arm should not be more than
94.    In a D.C. machine, the value of peripheral speed should not, normally, exceed
95.    In D.C. machines the width of the duct is usually
96.    D.C. machines designed with a large value of air gap length have
97.    In D.C. machines, or order to prevent excessive distortion of field form by the armature reaction, the field mmf must be made
98.    In D.C. machines, the ____ in field mmf results in increase in size and cost of machines.
99.    The operation of a D.C. machine with large air gap lengths is comparatively
100.   Which of the following methods may be adopted to reduce the effects of armature reaction ?

Electrical Engineering Materials Multiple Choice Questions and Answers pdf free download | Electrical Engineering Questions

1.    The converse of hardness is known as _______.
2.    On which of the following factors does the resistivity of a material depend ?
3.     ________ is a negatively charged particle present in an atom.
4.    The formula ____ determines the number of electrons that can be accommodated in any level.
5.   The tiny block formed by the arrangement of a small group of atoms is called the
6.   The co-ordination number of a simple cubic structure is
7.   The covalent bond is formed by _______.
8.    A perfect conductor has _______.
9.    The metal having the lowest temperature coefficient of resistance is
10.    Commonly used conducting materials are
11.    Which of the following materials is preferred for transmitting electrical energy over long distance ?
12.    The kinetic energy of a bounded electron is _______.
13.    A highly conductive material must have
14.    The conductivity of a conductor can be increased by
15.    Superconductivity is observed for ______.
16.    The superconductivity is due to _______.
17.    The value of critical field below the transition temperature will
18.    In a superconductor the value of critical density depends upon
19.    Superconductors are becoming popular for use in
20.    High resistivity materials are used in _______.
21.    Mercury as an electric contact material is
22.    An H.R.C. fuse is ________.
23.    Which of the following resistive materials has the lowest temperature co-efficient of resistance ?
24.    The coils of D.C. motor starter are wound with wire of
25.    The conductors have transport phenomena of electrons due to
26.    The transition temperature of mercury is ________.
27.    By increasing impurity content in the metal alloy the residual resistivity always
28.    The structure sensitive property of a super conductor is
29.    At transition temperature the value of critical field is
30.    Which of the following variety of copper has the best conductivity ?
31.    Constantan contains ________.
32.    Which of the following is the poorest conductor of electricity ?
33    ______ has zero temperature co-efficient of resistance.
34.    Piezoelectric materials serve as a source of _____ .   
35.    In thermocouples which of the following pairs is commonly used ?
36     ________ is viscoelastic.
37.    Carbon electrodes are not used in
38.    Solder is an alloy of _______.
39    ______ is most commonly used for making magnetic recording tape   
40.   Overhead telephone wires are made of ______.
41.  ______ is an example of piezoelectric material.
42.  _____ is the main constituent of glass.
43.  A good electric contact material should have all of the following properties except
44.  Most of the common metals have _____ structure.
45.  Which of the following affect greatly the resistivity of electrical conductors ?
46.  Thermonic emission occurs in _______.
47.   _____ is a hard solder.
48.  Addition of 0.3 to 4.5% silicon to iron _____ the electrical resistivity of iron.
49.  Super conductivity can be destroyed by _______.
50.  Non-linear resistors ________.
51.  A carbon resistor contains ________.
52.  Which of the following materials does not have covalent bonds ?
53.  In graphite, bonding is ______.
54.  Total number of crystal systems is _______.
55.  The number of atoms per unit cell in B.C.C. structure is
56.  The conductivity of a metal is determined by ______.
57.  The resistivity of a metal is a function of temperature because
58.  In a crystal, an atom vibrates at a frequency determined by
59.  Due to which of the following reasons aluminium does not corrode in atmost phere ?
60.  The impurity atoms is semiconductors
61.  Which of the following material is not a semiconductor ?
62.  Carbon resistors are used extensively because they are
63.  Carbon rods are used in wet and dry cells because
64.  Due to which of the following factors the brush wear rate is altered ?
65.  Which of the following are non-conductors of electricity?
66.  Carbon bearings are used under which of the following conditions ?
67.  Which of the following high resistance materials has the highest operating temperature ?
68.  Steel wire is used as _______.
69.  Low resistivity materials are used in _______.
70.  Platinum is used in ______.
71.  Which of the following is an advantage of stranded conductor over equivalent single conductor ?
72.  Due to which of the following reasons copper and aluminium are not used for heating elements ?
73.  Copper, even though costly, finds use in the windings of electrical machines because
74.  Which of the following materials is used for making coils of standard resistances ?
75.  Substances whose specific resistance abruptly decreases at very low temperature are called
76.  Which of the following materials is the best conductor of electricity ?
77.   _______ is the property of absorbing moisture from atmosphere.
78.  Thermocouples are mainly used for the measurement of ______.
79.  Due to which of the following fact, in India, aluminium is replacing copper ?
80.  The conduction of electricity, in semiconductors, takes place due to movement of
81.  Which of the following is a semiconductor material ?
82.  Selenium is _____ semiconductor.
83.   ________ has the best damping properties.
84.  The photo-electric effect occurs only when the incident light has more than a certain critical
85.  If the resistance of a conductor does not vary in accordance with Ohm's law it is known as
86.  Spark plug makes use of which of the following materials for insulation ?
87.  The forbidden gap in an insulator is ______.
88.  Which of the following factors affect resistivity of metals ?
89.  Effect of moisture on the insulating materials is to _______.
90.  Surface resistance of an insulating material is reduced due to the
91.  Superconducting metal in super conducting state has relative permeability of
92.  In conductors conduction of electricity takes place due to movement of
93.  The carbon percentage is least in _______.
94.  For a particular material the Hall coefficient was found to be zero. The material is
95.  The conductivity of an extrinsic semiconductor with temperature
96.  The current due to electron flow in conduction band is    the hole current in valence band.
97.  For a hole which of the following statements is incorrect ?
98.   _______ is an element used in semiconductors whose atoms have three valence electrons.
99.  The minority carrier concentration is largely a function of
100. For germanium the forbidden energy gap is _______.

Cables Multiple Choice Questions and Answers pdf free download | Electrical Engineering Questions and Answers

1.    The insulating material for a cable should have ______.
2.    Which of the following protects a cable against mechanical injury ?
3.    Which of the following insulation is used in cables ?
4.    Empire tape is _______.
5.    The thickness of the layer of insulation on the conductor, in cables, depends upon
6.    The bedding on a cable consists of _______.
7.    The insulating material for cables should _______.
8.    In a cable immediately above metallic sheath _____ is provided.
9.    The current carrying capacity of cables in D.C. is more than that in A.C. mainly due to
10.   In case of three core flexible cable the colour of the neutral is ______.
11    Cables are used for 132 kV lines.
12.    Conduit pipes are normally used to protect _____ cables.
13.    The minimum dielectric stress in a cable is at _____.
14.    In single core cables armouring is not done to ________.
15.    Dielectric strength of rubber is around
16.    Low tension cables are generally used upto _______.
17.    In a cable, the maximum stress under operating conditions is at
18.    High tension cables are generally used upto
19.    The surge resistance of cable is _______.
20.    PVC stands for _______.
21.    In the cables, the location of fault is usually found out by comparing
22.    In capacitance grading of cables we use a ______ dielectric.
23.    Pressure cables are generally not used beyond
24.    The material for armouring on cable is usually
25.    Cables, generally used beyond 66 kV are _______.
26.    The relative permittivity of rubber is ______.
27.    Solid type cables are considered unreliable beyond 66 kV because
28.    If the length of a cable is doubled, its capacitance
29.    In cables the charging current ______.
30.    A certain cable has an insulation of relative permittivity 4. If the insulation is replaced by one of relative permittivity 2, the capacitance of the cable will become
31.    If a cable of homogeneous insulation has a maximum stress of 10 kV/mm, then the dielectric strength of insulation should be
32.    In the cables, sheaths are used to ______.
33.    The intersheaths in the cables are used to _______.
34.    The electrostatic stress in underground cables is ______.
35.    The breakdown of insulation of the cable can be avoided economically by the use of
36.    The insulation of the cable decreases with
37.    A cable carrying alternating current has
38.    In a cable the voltage stress is maximum at
39.    Capacitance grading of cable implies
40.    Underground cables are laid at sufficient depth
41.    The advantage of cables over overhead transmission lines is
42.    The thickness of metallic shielding on cables is usually
43.    Cables for 220 kV lines are invariably
44.    Is a cable is to be designed for use on 1000 kV, which insulation would you prefer ?
45.    If a power cable and a communication cable are to run parallel the minimum distance between the two, to avoid interference, should be
46.    Copper as conductor for cables is used as
47.    The insulating material should have
48.    The advantage of oil filled cables is ______.
49.    The disadvantage with paper as insulating material is
50.    The breakdown voltage of a cable depends on
51.    It is difficult to maintain oil filled cables.
51.    In capacitance grading a homogeneous dielectric is used.   
52.    In congested areas where excavation is expensive and inconvenient 'draw in system' of laying of underground cablesis often adopted.
53.    Natural rubber is obtained from milky sap of tropical trees.
54.    Rubber is most commonly used insulation in cables.
55.    Polyethylene has very poor dielectric and aging properties.   
56.    The metallic sheath may be made of lead or lead alloy or of aluminum.

Switchgear Protections Multiple Choice Questions and Answers pdf free download | Electrical Engineering Questions

1.    The main function of a fuse is to _______.
2.    On which of the following routine tests are conducted ?
3.    SF6 gas _______.
4.    The arcing contacts in a circuit breaker are made of _____.
5.    Which  of the following  medium is employed for extinction of arc in air circuit breaker ?
6.    With which of the following, a circuit breaker must be equipped for remote operation ?
7.    Fault diverters are basically
8.    A thermal protection switch can protect against
9.    Arc in a circuit behaves as
10.    Thermal circuit breaker has
11.    Relays can be designed to respond to changes in
12.    Overload relays are of ______ type.
13.    Thermal overload relays are used to protect the motor against over current due to
14.    Magnetic circuit breaker has ______ trip action.
15.    D.C. shunt relays are made of _____.
16.    The relay operating speed depends upon _____.
17.    In order that current should flow without causing excessive heating or voltage drop, the relay contacts should
18.    Circuit breakers usually operate under _____.
19.    Circuit breakers are essentially ______.
20.    The current zero interruption, in oil and air blast circuit breakers, is achieved by
21.    Air blast circuit breaker is used for ______.
22.    An efficient and a well designed protective relaying should have
23.    Burden of a protective relay is the power
24.    Directional relays are based on flow of
25.    A differential relay measures the vector difference between
26.    A transmission line is protected by _____.
27.    Large internal faults are protected by _____.
28.    When a transmission line is energized, the wave that propagates on it is
29.    Protective relays are devices that detect abnormal conditions in electrical circuits by measuring
30.    The voltage appearing across the contacts after opening of the circuit breaker is called______voltage.
31.    Ionization in circuit breaker is facilitated by _____.
32.    In a circuit breaker the basic problem is to ____.
33.    Overheating of relay contacts or contact born out is due to
34.    Interruption of large currents by relay requires
35.    Shunt capacitance is neglected while considering
36.    The arc voltage produced in A.C. circuit breaker is always
37.    The time of closing the cycle, in modern circuit breakers is
38.    Insulation resistance of high voltage circuit breakers is more than
39.    H.R.C. fuses provide best protection against ______.
40.     The ground wire should not be smaller than No ______ copper.
41.    The delay fuses are used for the protection of ________ .
42.    Which of the following is the least expensive protection for overcurrent is low voltage system ?
43.    Resistance grounding is used for voltage between
44.    The contacts of high voltage switches used in power system are submerged in oil. The main purpose of the oil is to
45.    In Railway applications ______ circuit breaker is used.
46.    To protect most of the electrical equipment handling low power, the types of relays used are
47.    Wave trap is used to trap waves of _____.
48.    Ungrounded neutral transmission system is not recommended because of system
49.    The reflection co-efficient at the open circuited end of a transmission line.
50.    For the protection of power station buildings against direct strokes the requirements are
51.    The line insulation is _____ the insulation level of the station equipment.
52.    The interaction between a transmission line and communication line is minimized by
53.    When a wave propagates on a transmission line, it suffers reflection several times at
54.    Which of the following statements is incorrect?
55.    Discrimination between main and back up protection is provided by the use of relays which are
56.    Induction cup relay is operated due to changes in
57.    A.C. network analyser is used to solve problems of
58.    Which of the following statements is incorrect ?
59.    Short-circuit currents are due to ______.
60.    To reduce short circuit fault currents are used.
61.    Bus coupler is very essential in arrangement
62.    For cost and safety, the outdoor substations are installed for voltages above
63.    The short circuit in any winding of the transformer is the result of
64      ______ relays are used for phase faults on long line.
65.   For which of the following protection from  negative  sequence  currents  is provided ?
66    ______ relay is preferred for phase fault on short transmission line.
67.    Distance relays are generally ______.
68.    For which of the following ratings of the transformer differential protection is recommended ?
69.    A _______ is used to measure the stator % winding temperature of the generator.
70.    The under voltage relay can be used for _____.
71.    The relay with inverse time characteristic will operate within
72.    The single phasing relays are used for the protection of _____.
73.    Which of the following devices will receive voltage surge first traveling on the transmission line ?
74.    Which of the following parameter can be neglected for a short line ?
75.    Series reactors should have _____.
76.    Which of the following circuit breakers has high reliability and minimum maintenance ?
77.    Arc in a circuit breaker is interrupted at ______.
78     _______ transmission line has reflection coefficient as one.
79.    What will be the reflection co-efficient of the wave of load connected to transmission line if surge impedance of the line is equal to load ?
80.    The inverse definite mean time relays are used for over current and earth fault protection of transformer against
81.    Over voltage protection is recommended for
82.    Air blast circuit breakers for 400 kV power system are designed to operate in
83.    Overfluxing protection is recommended for
84.    Series capacitors are used to ______.
85.    Admittance relay is _______ relay.
86.    The material used for fuse must have
87.    If the fault occurs near the impedance relay, the VII ratio will be
88.    The torque produced in induction type relay (shaded pole structure) is
89.    The steady state stability of the power system can be increased by
90.    The inductive interference between power and communication line can be minimized by
91.    The power loss is an important factor for the design of
92.    A fuse is connected ______.
93.    H.R.C. fuse, as compared to a rewirable fuse, has
94.    The fuse rating is expressed in terms of ______.
95.    The fuse blows off by ______.
96.    On which of the following effects of electric current a fuse operates ?
97.    An isolator is installed ______.
98.    A fuse in a motor circuit provides protection against
99.    Protection by fuses is generally not used beyond
100.    A fuse is never inserted in ______.