1/100
The strength of an electromagnet can be increased by
2/100
The best conductor amongst the following is
3/100
Energy stored in a capacitor is given by
4/100
An inductor at t =0^ + with initial current I_o acts as a
5/100
In the given circuit in below figure, ---------through the galvanometer
6/100
Potential difference between A and B in the given circuit is
7/100
Power in 5Ω of circuit shown below is 20 watt, then the resistance Ris
8/100
The emf induced in the armature of a shunt generator is 600 V. The armuture resistance is 0.1 ohm if the armature current is 200A, the terminal voltage will be
9/100
If W ₑ is the constant loss and Rₐ is the armature resistance of a de generator, then load curren I_L orresponding to maximum efficiency is
10/100
In generators, the rule used to know the direction of induced emf is
11/100
The demagnetizing flex in dc gerators
12/100
Which DC motor is preferred for elevators
13/100
A 220V dc series motor is taking a current of 40A. Resistance of a armature= 0.5Ωand resistance of series field is 0.25Ω What is the back emf when there is no brush drop
14/100
Rapid stopping of an electric motor by momentarily its connections to the supply is called
15/100
In dc motors, the condition for maximum power is
16/100
The metiral used for making the coil of a standard resistance is
17/100
Creeping errors are found in
18/100
Sensitivity of a voltmeter is expressed as
19/100
In a MC instrument, the deflecting torque is proportional to
20/100
The period of 1/50 sec corresponds to a frequency of ----- Hz
21/100
The average value of a sine wave is 100A. RMS value of the same wave is
22/100
For the wave shown below, the average value is
23/100
In an R-L-C circuits, v(t)=20 sin (314t+ 5π/6) and i(t)=10 sin (314t+2π/3). The power factor of the circuit is
24/100
Which point on the slip/torque graph shown in below figure represents the pull-out torque of an induction motor?
25/100
The eddy current loss of a 1-Φ transformer at a frequency of 25 Hz is 40W, It's eddy current loss at 50 Hz frequency
26/100
The equivalent resistance of a transformer referred to secondary is given by
27/100
The voltage drop in a transformer is given by
28/100
Distribution transformers are designed to keep core losses minimum and copper losses are relatively less important because
29/100
The transformer oil is used in transformer to provide
30/100
Sumpner's test on two identical transformers yields information about
31/100
A ∆/Y transformer has phase to phase voltage transformation ratio of a : 1 The voltage ratio of Y/∆ is given by
32/100
A 3-phase 4-pole, 24 slot alternator has its armature coils short pitched by one slot. Its g K_c will be
33/100
When two 50 Hz 3 - Φ alternators are operated in parallel in one of the machines tends to take more- than its proportional amount of load. In order to distribute the load proportionately and still operate at rated frequency, it is necessary to
34/100
The speed of an alternator is changed from 3000 rpm to 1500 rpm. The generated emf / phase will become
35/100
If load (or torque) angle of 4-pole synchronous motor is 8° (elect), its value in mechanical degrees is
36/100
The 'V' curves of a synchronous motor are drawn between ----and------
37/100
A cylindrical rotor synchronous motor is switched on to the supply with its field windings shorted on themselves. It will
38/100
When the applied voltage to an induction motor is varied keeping the frequency at rated value
39/100
A 3-phase 400 V 4-pole induction motor is fed from a 3-phase, 400V, 50 Hz supply 1440 rpm. The frequency of the rotor EMF is --- Hz
40/100
Out of the following methods of starting a three-phase induction motor which one requires six stator terminals?
41/100
In a 3-phase slip-ring induction motor, brushes are connected to
42/100
Which point on the slip/torque graph shown in below figure represents the pull-out torque of an induction motor?
43/100
Main advantage of capacitor run motor is
44/100
Which of the following motors is used in mixers
45/100
Induced draft fans are located at
46/100
The electrostatic precipitator is used to collect
47/100
Major share of power produced in India is through
48/100
In hydel plant, the mechanical energy to run the alternator is obtained from
49/100
Demand factor is given by
50/100
The main function of a fuse is to
51/100
Sparking between contacts can be reduced By inserting
52/100
The arcing contacts, in a circuit breaker are made of
53/100
The relay operating speed will not depend upon
54/100
The number of contacts in a 3-phase circuit breaker is
55/100
If height of the tower increases then sag practically
56/100
To reduce corona less the shape of the conductor is
57/100
The number of strands in a stranded conductor can be determined by (N) =
58/100
Insulation resistance of the cable is given by
59/100
in H.V.D.C. transmission charging current are there
60/100
High voltage transmission lines consists of
61/100
Service mains feed electric power to
62/100
The purpose of guard rind is to
63/100
in a distribution system which of the following items shares the major for cost
64/100
The distributors in residential areas are
65/100
Trapezoidal speed time curve pertains to
66/100
The speed of the train estimated taking in account the stoppage time at a station in addition to the actual running lime between stops, is called the speed
67/100
The type of dc motor used in electric traction is
68/100
Kando system used for train electrification is the name used for
69/100
The requirement for ideal traction system is
70/100
Longer consisting period results in
71/100
The current collector that can be employed with different speeds under all wind conditions and stiffness of over head electrification is known as
72/100
Specific energy consumption is minimum is services
73/100
The material for conductor in a cable is
74/100
The insulation resistance test is performed on power line with
75/100
The cheapest internal wiring is
76/100
The I_cbo in a transistor can be reduced by reducing
77/100
In an NPN transistor, the leakage current is due to
78/100
A full wave rectifier with I phase ac input is ----- convertor
79/100
In voltage amplifiers the load resistance should he
80/100
An amplifier without feedback has a gain of 1000. What is its gain with a negative feedback of 0.009?
81/100
In a piezoelectric crystal oscillator, the oscillation or tuning frequency is linearly proportional to the
82/100
An AND gate
83/100
Which of the following complete sets of logic gates designated as universal gates is
84/100
Ann bit A/D converter is required to convert an analog input in the range 0.5V to an accuracy of 10mV. The value of n is
85/100
D-Flif-Flop can be made from a J-K Flip-Flop by making
86/100
In a wein bridge oscillator if the resistances in the positive feedback circuit are decreased, the frequency
87/100
When cathode of a thyristor is made more positive than its anode, then
88/100
The Snubber circuit is used in thyristor circuits for
89/100
In an SCR if latching current is I_{L} and holding current is I_{H} then the following relation hold good
90/100
Which one is most suitable power device for high frequency (<100 KHz) switching application
91/100
For stator voltage control of 3 phase induction motor which of the following converter is used if the supply is 3 phase 4C, 50Hz
92/100
A dc step down chopper has T_on of I ms and its frequency is 500 Hz. What will be its duty ratio"?
93/100
The output voltage and current waveform of a single phase fully controlled and half controlled converter will be same provided the extinction angle ẞ is less than
94/100
A PWM inverter is capable of producing the following type of output voltage
95/100
In a single phase to single phase cycloconverter if α₁ and α₂ are the trigger angles of positive converter and negative converter. then
96/100
When fed from a fully controlled converter, a dc motor, driving an active load can operate in
97/100
Program Status Word (PSW) in 8051 is bit
98/100
Internal clock frequency of 8051 is
99/100
Which of the following register has no internal address?
100/100
The number of registers in 8051 is
Result: