1/100
There are two A & B. A is 20 times longer than B and has half the cross section of that of B. If the resistance of B is 1Ω the resistance of A will be
2/100
A double squirrel-cage induction motor has
3/100
A 100 watt light bulb burns on an average of 10 hours a day for one week. The weekly consumption of energy will be---- units
4/100
Which of the following theorem is applicable for both linear and non-linear circuits
5/100
The unit of electric intensity is
6/100
If the dielectric of a capacitor as replaced by a conducting material the
7/100
The magnetic field intensity (in A/m) at the centre of a circular coil of diameter Im and carrying 4 Currrent of 2A is
8/100
Two coupled coils with L₁ = L₂ = 0.16H have a coupling coefficient of K = 0.8. The turn ratio N₁/N₂ is
9/100
The field current of a shunt excited generator is
10/100
A series generator is running at its normal speed and output is open circuited. The terminal voltage developed is
11/100
The field resistance of a dc shunt generator is 200 ohms, this resistance line drawn on the open circuit characteristic, cut the o.c. curve at a point (400V, 2.0A). The emf developed is
12/100
The essential condition for satisfactory parallel operation of two generators is that they should have the same
13/100
The current drawn by a 120 V dc stunt motor of armature resistance of 0.5 ohm and back emf 110V is ------ amps
14/100
The maximum torque of dc motors is limited by
15/100
The main disadvantage of 3-point starter is
16/100
Performance of larger dc machines regarding commutation and temperature rise at full load can be checked by --- test
17/100
Air friction damping is used in -------- type of instrument
18/100
The burden of current transformer is expressed in
19/100
Loss of charge method is used for measurement of
20/100
A 200 ohms metallic strain guage with gunge factor 2.0 when subjected to a strain of 500 micro- strain will have a total change in resistance of
21/100
A capacitive circuit of 50 uF and of negligible resistance is connected across a 300V, 50 Hz 1-phase supply. The rms valve of current drawn by the circuit is
22/100
An alternating current of frequency 50 Hz and maximum valve 200A is given as
23/100
A series resonant circuit has
24/100
Three equal impedances are first connected in delta across a three phase balanced supply. If the same impedances are connected in star across the same supply then
25/100
W, and W. are the readings of two walimeters used to measure power of a 3 phase balanced load. The reactive power drawn by the load is
26/100
In an ideal transformer which of the following is true
27/100
The ratio of core loss to copper loss at full load is 0,5, the maximum efficiency occurs when the load is
28/100
Mineral oil is used in tansformer as
29/100
The p.u equivalent resistance and reactance drops of a transformer are 2.0 and 4.0 respectively if the transformer operates at 0.6 lagging p.f., the percentage of voltage regulation is
30/100
The losses are measured in auto transformer, when it is operating at no load are 150W. Iron of this transformer at full load operation are
31/100
During the SC test, power drawn by the primary winding is predominantly observed by
32/100
In parallel operationload sharing by transformers is according to
33/100
When speed of alternator is changed from 3600 rpm to 7800 rpm, the generated emi per phase will be become
34/100
The regulation of an alternator is
35/100
In case of turbo-alternators, rotor is made of
36/100
A synchronous motor is supplied a load at unity p.f. If the load on the motor is increased keeping its excitation and terminal voltage constant, then the p.f
37/100
When synchronous motor is running at synchronous speed, the damper winding produces
38/100
While starting a synchronous motor by induction motor action its field winding should be
39/100
The stator core of a three phaseinduction motor is laminated in order to reduce the
40/100
A 4 pole, 50Hz, 3 phase induction motor is running with a slip of 4%, the rotor induced voltage frequency is
41/100
In an induction motor if the flux density of rotor is reduced to half of its normal value, the torque will be
42/100
In a shaded pole motor, shading coils are used to
43/100
Which of the following motors uses a centritugal switch
44/100
To improve the efficiency of thermal power plant ------ is placed between boiler and turbine
45/100
A consumer has to pay lesser fixed chargell in
46/100
The area under load curve gives
47/100
The reserved generating capacity available for service under emergency conditions which is not kept in operation but in working order
48/100
By the use of which of the following power factor cannot be improved
49/100
In which of the following a circuit breaker must be equipped for remote operation
50/100
A mho relay is normally used for protection of
51/100
A circuit breaker normally operates -----------
52/100
A transmission line is protected by
53/100
Bus bar protection is achieved by using ------relays
54/100
The fact that a conductor carries more current on the surface as compared to core is known as
55/100
In overhead transmission lines the effect of capacitance can be neglected when the length of line is
56/100
A4 insulater string has string efficiency of 80%. 45kV is applied to the string. What is voltage across lowest unit
57/100
Electric stress is expressed in terms of
58/100
A back to back HVDC link can be advantageous compared to AC primarily because
59/100
The capacitance and inductance per unit length of a 3-phase line, operating at 110kV are 0.01 microfired and 2.5 mH. The surge impedance of the line is
60/100
The percentage regulation of an overhead transmission line can be zero when the load power factor is
61/100
The distributors for residential areas are
62/100
Insulation resistance of a cable is
63/100
The sag of a transmission line is least affected by
64/100
Which of the following is an advantage of electric traction over other methods of traction
65/100
The speed of the train estimated taking into account the time of stop at a station in addition or the actual running time between stops, is known as
66/100
Metadyne contol method is employed in which traction system
67/100
A train has a schedule speed of 36 km per hour on a level track. If the distance between the stations is 2 km and the stoppage is 30 seconds the actual time of run will be
68/100
The speed time curve for a local train is shown in Figure. In this AB represents
69/100
Specific energy consumption is least in
70/100
Frequency of single phase traction system is
71/100
The traction motor used in tram ways is
72/100
Which of the following wiring system is commonly used for light/fan load in domestic and commercial buildings
73/100
Why multi-stand conductor are preferred over solid conductors
74/100
Which wiring system is employed in mechanical workshops
75/100
What in the average resistance of a human body
76/100
In what state is a silicon diode, if the voltage drop across it is about 0.7V
77/100
A3-phase diode bridge rectifier is fed from a 400 V rms. 50 Hz 3 phase AC source. If the load is purely then peak instantaneous output voltage is equal to
78/100
The cathode ray oscilloscope displays the graph of the waveforms based in
79/100
The op-amp comparator circuit uses
80/100
An integrator op-amp uses what element in the feedback path
81/100
Upon what principle does a relaxation oscillator operate
82/100
An oscillator is described by
83/100
The 2's compliment of the mumber of 1010101
84/100
The number of comparators in a parallel conversion type 8 bit analog to digital convener is
85/100
What is the only input combination that will produce a high at the output of a five input AND gate
86/100
What will be the state of Q and Q' after a flip-flon has been reset
87/100
Which statement is true for latching current
88/100
Thyristor can be protected from over voltage by using
89/100
UJT is known as
90/100
The TRIAC is equivalent to
91/100
The advantage of using a free wheeling diode with bridge type ac/dc converter is
92/100
A power chopper converts
93/100
A three phase full converter is supplying a purely resistive load at 300 V dc for 0° firing angle. The output voltage for 90° firing angle would be
94/100
A single phase ac voltage controller is controlling current in a purely inductive load. If the firing angle of the SCR is α what will be the conduction angle of the SCR
95/100
Which braking is not possible in series motor
96/100
Full form of VVVF control
97/100
The 8051 microcontroller is of ---- pin package as ---- a processor
98/100
Serial port interrupt is generated, if ----- bits are set
99/100
After reset, SP register is initialized to address
100/100
8051 series has how many 16 bit registers
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