1/100
Hard magnetic materials are characterized by
2/100
In dielectric matelials. the dielectric loss angle will be
3/100
The suitable material used for heating elements and loading rheostats is
4/100
A battery is charged at a potential of 15 volts for 8 hours when the current is 1OA. The battery on discharge supplies a cunent of 5A for 15 hours. The mean tenninal voltage during discharge is 14 volts. The watt-hour efficiency of the battery is ------.
5/100
If v, w and q stand for voltage, energy and unit positive charge respectively, then 'v' can be expressed as
6/100
Two straight parallel conductors are kept horizontally one above the other. If the upper wire suspends in air without any support, then the direction of flow of cunent in the wires should be -----
7/100
Which of the following statements is not correct?
8/100
Same mass of copper is drawn into 2 wires of 1 mm thick and 3 mm thick. Two wires are connected in series and current is passed. Heat produced in the wires is in the ratio of
9/100
A current of i = 300t is suddenly applied to an inductance of 1mH. Find the induced voltage?
10/100
An ideal voltage source of 10 v, an ideal current source of 1A and a pure resistance of 5Ω are connected in parallel. Find the cun•ent flowing through 5Ω resistance?
11/100
The resistance of a copper wire is R ohms. The wire is stretched to its double length. The new resistance is _____ Ω.
12/100
The number of 2 µF, 400 V capacitors needed to obtain a capacitance value of 1.5 µF rated for 1600 V.
13/100
The armature resistance of a 6 pole lap wound d.c machine is 0.05Ω. If the armature is rewound using a wave winding, then the armature resistance will be _____
14/100
If the speed of a d.c motor increases with load torque. then it is a _____
15/100
A d.c series motor is driving a load whose torque valies as square of the speed. When the speed is 250 rpm. the line current is 15 A. If speed is 500 rpm. then the line current is likely to be ____
16/100
The tenninal voltage of a d.c series generator is 150 V when the load current is 5A. Take the combined resistance of armature and series field as 1Ω. If the load current is increased to 1OA for the same generated e.m.f, the tenninal voltage will be ____
17/100
Two DC machines are tested by Hopkinson test. The rating of each machine is 250 kW. The power input during this test would be around ______
18/100
The interpole nunf is propoltional to ______
19/100
The number of parallel paths in the annature winding of a four pole. wave connected DC machine having 22 coil side is ____
20/100
To have sparkles commutation, the armature reaction effect in a DC machine is neutralized by ____
21/100
A single phase energy meter is operating on 230 V, 50 Hz supply with a load of 20 A for 2 hours at unity power factor. The meter makes 1380 revolutions in that period. The meter constant is ____
22/100
A moving coil instrument gives full scale deflection for 1 mA and has a resistance of 5 ohms. If a resistance of 0.55 ohms is connected in parallel to the instrument, what is the maximum value of current it can measure?
23/100
Which of the following types of instruments can be used to detennine the rms value of AC voltage of high magnitude (10 kV) and of any wave shape?
24/100
Which of the following materials is used in the fabrication of swamping resistance of a PMMC instrument?
25/100
Permanent magnet moving coil ammeters have unifonn scales because ____
26/100
The most efficient fonn of damping employed in electrical instruments is ____
27/100
An AC series circuit consisting of a resistance of 6 ohms and an inductive reactance of 8 ohms is connected to a single phase 200 V, 50 Hz AC supply. The current flowing in the circuit would be ____
28/100
The voltage and current in a circuit are given by v = 10 sin (ωt — Ï€/6), i = 10 sin (ωt + Ï€/6). The power consumed is given as ____
29/100
In a circuit, the voltage and current are given as (10 + j5) volts and (6 + j4) amps respectively. The reactive power in the circuit is ____
30/100
When two watt-meter method of measurement of power is used to measure power in a balanced three phase circuit, if one of the wattmeter readings is zero, then ____
31/100
A coil having a resistance of 5 ohms and inductance of 0.1 H connected in series with a capacitor of 50 μF. A constant altemating voltage of 200 V is applied to the circuit. The voltage across the coil at resonance is ____
32/100
Two impedances are connected in series. Across each impedance a voltmeter is connected and another voltmeter is connected the combination of two impedances. The phase angle between the voltages across the two impedances when all the three voltmeters read equal value ____
33/100
A 200 / 400 V ratio, single phase transformer has a secondary winding resistance of 0.5 Ω. The primary resistance is 0.1 Ω. The total resistance is referred to primary should be ____
34/100
The regulation of two winding transfonner is 5% at full load unity power factor (pf). At full load 0.8 pf lagging the regulation would be
35/100
A 10 KVA, 100/300 V two winding transformer is used as an auto transfonner by connecting the two windings in series to supply a 300 V load from a 400 V AC supply. The maximum KVA which can be supplied by an auto transformer is
36/100
A three phase transfonner is composed of three transformers connected in delta-delta. Its rating is 100 KVA. If one of the units gets damaged and it is operated in open delta, then the rating will be _____
37/100
The ratio of the primary' to secondary voltage of a transfonner is 2:1. If an auto transfonner is used instead of a two winding transformer, then the saving in terms of weights of a copper required will be _____
38/100
A two winding transfonner has iron losses and full load copper losses equal to W watts each. It is tested along with another similar transfonner for back to back test. The total power input would be ____
39/100
If the power factor of an altemator is zero lagging the armature reaction is ____
40/100
The reactive power output of a cylindrical rotor altemator is maximum when ____
41/100
The full pitch coil in a synchronous machine has a span of 18 slots. To eliminate third harmonics, the coil span would be ____
42/100
An under excited synchronous motor operates at ____
43/100
Synchronous motors are used in situations where ____
44/100
A 5 HP, 3-phase, 400 V star connected squirrel cage induction motor meant to drive a milling machine. At starting the machine takes the current about ____
45/100
A 3-phase induction motor has a stalting torque of 200 Nm when switched on directly to supply. if an auto transformer with 50% tapping is used for starting. The starting torque would be ____
46/100
A 400 V, 50 Hz three phase induction motor rotates at 1440 rpm on full load. The motor is wound for ____
47/100
While starting a three-phase induction motor, a star-delta starter is used to ____
48/100
Torque developed by a three-phase 400 V induction motor is 100 Nm. If the applied voltage is reduced by 200 V, then the torque developed is ____
49/100
When a single-phase supply is connected across a single-phase winding, the nature of magnetic field produced is ____
50/100
A capacitor start capacitorrun motor has two capacotors , than ____
51/100
In order to have a lower cost of power generation,____
52/100
A station operates with load factor and plant capacity factor of 0.75 and with a maximum demand of 100 MW. The reserve capacity is ____
53/100
A hydro power plant supplied by a river with a discharge of 3000 m3/sec at a head of 30 meters, with a plant efficiency of 79% develops a power nearly ____
54/100
An industlial consumer has a load of 1500 kW at 0.8 pf (lag) for 12 hours and 1000 kW at u.p.f for 12 hours during the day. The daily load factor is ____
55/100
The area under the daily load curve gives ____
56/100
The material used for the fuse must have ____
57/100
Making capacity of circuit breaker is equal to ____
58/100
In a thyrite lightning arrester, the resistance ____
59/100
The use of high-speed breaker ____
60/100
Which relay is more susceptible to electromagnetic interface?
61/100
Distance relay is the best example of ____
62/100
Switching of unloaded transformer during zero crossing of voltage wave generates ____
63/100
The resistance and reactance of short transmission line are equal. At zero regulation, the load will be ____
64/100
The presence of earth in case of overhead lines ____
65/100
The sag for a span of 350m, if the ultimate tensile strength of conductor is 5000 kg, factor of safety is 2 and weight of conductor is 0.550 kg/m is nearly ____
66/100
A short line with a reactance of 20 ohms and negligible resistance operates with a sending end voltage of 132 kV and receiving end voltage of 126 kV. The maximum power that can be transmitted with this voltage profile is about ____
67/100
A string of six insulators has self capacitances equal to 10 times the pin-to-eatth capacitance. The string efficiency will be around ____
68/100
The propagation constant of a transmission line is (0.15 x 10⁻³ + j 1.5 x 10⁻³). The wave length of the traveling wave is ____
69/100
The insulation resistance of a cable of length 10 km is 1 MΩ. For a length 100 km of the same cable. the insulation resistance will be ____
70/100
In a three phase, 4 wire AC system, if the loads are balanced, then current in the neutral wire is ____
71/100
For combined power and lighting load, the distribution system used is ____
72/100
In an instument transformer phase angle error occurs due to ____
73/100
A typical active load is ____
74/100
Which of the following statements is True?
75/100
A locomotive with a mass of 50,000 kg on a track whose coefficient of adhesion is 20% will produce a tractive effort of (around)____
76/100
Choose the correct statement from the following?
77/100
The specific energy output of a traction motor is 'X' watt-hour per tonne-km and the efficiency of gear is 0.5 and the efficiency of motor is also 0.5. The value of specific energy consumption is ____
78/100
Which of the following is the characteristic of main line service in electric traction?
79/100
Electric braking through plugging without any additional corrective measure is possible for ____
80/100
An electric drive consists of ____
81/100
Most commonly used AC motor is ____
82/100
A 60 W lamp gives a luminous flux of 1500 lumen. Its efficiency is ____
83/100
The size of wire for wiring a 15 Amps socket outlet in kitchen should be ____
84/100
The size of continuous earth wire used with cables in domestic installation should not be less than ____ in any case.
85/100
The minimum clearance above ground of the lowest conductor of an overhead line for high voltage lines upto 11 KV erected along a street is ____
86/100
The load on each power sub-circuit should be normally restricted to ____
87/100
The main advantage of looping in system of wiring is ____
88/100
In a CRO by changing the time base, the following can be changed?
89/100
A monostable multivibrator is also called ____
90/100
The master-slave JK flip-flop is an example of ____
91/100
Two-input XNOR gate gives HIGH output ____
92/100
The conduction loss versus device current characteristic of a Power MOSFET is best approximated by a/an ____
93/100
A step-up chopper is used to feed a load of 400 V d.c from a 250V d.c source. The induction cunent is continuous if the off time of the switch in 20μs. The switching frequency of the chopper in KHz is ____
94/100
The output voltage wave form of a three phase square-wave inverter contains ____
95/100
Microcontroller 8051 has ____ bits of the data bus.
96/100
A voltage source 200 sin (314t) is applied to a thyristor controlled half wave rectifier with resistive load of 50 ohms. If the firing angle is 30° with respect to supply voltage waveform. the average power in the load is ______
97/100
A single phase AC regulator with an inductive load has the following details: source voltage = 230V, frequency = 50 Hz and ωL=5 ohms The control range of the firing angle (α) is ____
98/100
When a bipolar junction transistor is operating in the saturation mode, which of the following statements is true about the slate of its collector-base (CB) and the base emitter (BE) junction? ____
99/100
The increasing order of speed of data access for the following device is: i. Cache Memory ii. CD-ROM iii. Dynamic RAM iv. Processor Registers v. Magnetic Tape
100/100
The octal equivalent of the HEX number AB.CD is
Result: