1/100
A 24 V battery of internal resistance r=4 ohm is connected to a variable resistance R. The rate of heat dissipated in the resistor is maximum when the current drawn from the battery is I.They current drawn from the battery will be (I/2) when R is equal to
2/100
A battery is connected to a resistance causing a current of 0.5 A in the circuit. The current drops to 0.4 A when additional resistance of 5 Ω is connected in series The current will drop to 0.2 A when the resistance is _
3/100
Superposition theorem is not applicable for _
4/100
A load is connected to an active network. At the terminals to which the load is connected, Rth = 10Ω and vth = 60V. The maximum power supplied to the load is
5/100
Which of the following is not a conducting material ?
6/100
For an insulating material, dielectric strength and dielectric loss should be respectively _
7/100
Which one of the following materials has the highest dielectric strength?
8/100
Armature core of DC machine is laminated to reduce _
9/100
A shunt generator has a critical field resistance of 200Ω at a speed of 800 r.p.m. if the speed of the generator is increased to 1000 r.p.m. What is the change in the critical field resistance of the generator?
10/100
The overall efficiency of a DC shunt generator is maximum when its variable loss equals _
11/100
In a machine, for the same number of slots and same current in the armature conductor, which one of the following will induce higher emf?
12/100
A series motor drawing an armature current of la is operating under saturated magnetic conditions. The torque developed in the motor is proportional to _
13/100
when is the mechanical power developed by a DC motor maximum?
14/100
Which of the following are the variable losses in a rotating machine?
15/100
The speed of a DC motor is related to the back emf and flux in the following ways:
16/100
For controlling the vibration of the disc of AC energy meter, damping torque is produced by _
17/100
Which of the following bridges will be used for the measurement of very low resistance ?
18/100
A current transformer has a phase error of +30 . The phase angle between the primary and secondary current is _
19/100
If one the control springs of a Permanent Magnet Moving Coil ammeter is broken then, when connected it will read _
20/100
The circuit comprises a coil of resistance R and inductance L, in parallel with an ideal capacitor C. At resonant frequency, the impedance of the parallel combination is _
21/100
In RLC circuits , the current at resonance is _
22/100
The power consumed by a coil is 300 W when connected to a 30 V DC source and 108 W when connected to a 30 V AC source. The reactance of the coil is _
23/100
If the source of 200 V rms supplies active power of 600 W and reactive power of 800 VAR.The rms current drawn from the source _
24/100
A 3-phase delta connected symmetrical load consumes P watt of power from a balanced supply . If the same load is connected in star to the same supply , then what is the power consumption?
25/100
The desirable properties of transformer core material are _
26/100
Two single phase 100 kVA transformers, each having different leakage impedance are connected parallel. When a load of 150 kVA at 0.8 power factor lagging is applied then _
27/100
The most essential condition for parallel operation of two 1-Ø transformers is that they should have the same _
28/100
It is advice to use auto-transformer if the transformation ratio is _
29/100
In a transformer, zero voltage regulation at full load is _
30/100
In the frequency of input voltage of a transformer is increased keeping the magnitude of voltage unchanged, then _
31/100
Which of the following connection of transformer will give the highest secondary voltage?
32/100
Two mechanically coupled alternators delivers power at 50 Hz and 60 Hz respectively. The highest speed of the alternator is _
33/100
Which one of the following methods would give a higher than actual value of regulation of an alternator?
34/100
In synchronous alternator, which of the following coils will have emf closer to sine wave form?
35/100
V – curve of synchronous motor shows the variation of _
36/100
An ideal synchronous motor has no starting torque because the _
37/100
A synchronous motor is operating on no load at unity power factor . if the field current is increased , the power factor will become_
38/100
When the supply voltage for induction motor is reduced by 10% the maximum running torque will nearly _
39/100
As compared to DOL starting, a cage induction motor with star-delta starting shall have_
40/100
A 6- pole, 50 Hz single phase induction motor runs at a speed 900 rpm. The frequency/frequencies of current in the cage rotor will be _
41/100
The Torque – slip characteristics of a poly phase induction becomes almost linear at small values of slip , because in this range of slips
42/100
A capacitor – start single – phase induction motor is used for
43/100
In a split – phase motor, the running winding should have
44/100
In pumped storage scheme, the generator is also used as
45/100
The flow – duration curve at a given head of a hydro electric plant is used to determine the _
46/100
In a nuclear power station using boing water reactor (BWR), water is used as
47/100
In a nuclear reactor , chain reaction is controlled by introducing _
48/100
For harnessing low variable water heads , the suitable hydraulic turbine with reaction and adjustable vanes runners is:
49/100
The re-striking voltage is measured in _
50/100
The rate of rise of re-striking voltage ( RRRV) is dependent upon _
51/100
A Buchholtz relay is used for _
52/100
Which one of the following grounding methods is used to reduce the tower footing resistance where an earth resistance is low?
53/100
A lighting arrestor connected the line and earth in power system _
54/100
For a transmission line with resistance R, reactance X, and negligible capacitance, the transmission line parameter A is _
55/100
The insulation resistance of a single core cable is 200 MΩ/km. The insulation resistance for 5 km length is _
56/100
Which one the following equations is correct ?
57/100
When is the Ferranti effect on long overhead lines experienced ?
58/100
Whenever the conductors are dead – ended or there or these is a change in the direction of transmission line, the insulators used are of the _
59/100
In a three unit insulator string , voltage across the lowest unit 17.5 kV and string efficiency is 84.28% . The total voltage across the string will be equal to _
60/100
In the case of a HVDC system, there is _
61/100
In an HVDC system: _
62/100
Disruptive corona begins in smooth cylindrical conductors in air at NTP if the electric filed intensity at the conductor surface goes up to _
63/100
In a short transmission line, voltage regulation is zero when the power factor angle of the load at the receiving end side is equal to _
64/100
Long distance railways use which of the following?
65/100
Quadrilateral speed – time curve pertains to which of the following services?
66/100
In case of _ free running and coasting periods are generally long
67/100
The voltage used for suburban trains in DC system is usually _
68/100
Which of the following will not decrease as a result of introduction of negative feedback?
69/100
In a closed loop control system _
70/100
The effect of integral control on the steady state error ess and that on the relative stability Rs of the system is _
71/100
As compared to a closed loop system , an open loop system is _
72/100
A fuse is _
73/100
As per recommendation of ISI the maximum load that can be connected in one sub-circuit is_
74/100
Lamp in street lighting are all connected in_
75/100
The resistance of earth should be _
76/100
A source follower using an FET usually has a voltage gain which is _
77/100
Dark current in a semiconductor photodiode is _
78/100
In a centre tap full wave rectifier , 100 V is the peak voltage between the centre tap and one end of the the secondary what is the maximum voltage across the reverse biased diode?
79/100
In an inverting amplifier, the two input terminals of an ideal op-amp are the same potentil because _
80/100
In the different and common mode gains of a differential amplifier are 50 and 0.2 respectively, then the common mode rejection ratio will be _
81/100
The barkhausen criterion for sustained oscillations is _
82/100
In an RC phase shift oscillator , the minimum number of RC networks to be connected in cascade will be _
83/100
The decimal equivalent of the hexadecimal number (BAD)16 is _
84/100
The function F = ABĀ + ABC + ĀBC + ĀBC̄ can be reduced to which one of the following _
85/100
If the output of a logic gate is ‘1’ when all its inputs are at logic ‘0’,the gate is either _
86/100
Number of comparators required to build a 5-bit Analog to Digital converter is _
87/100
Power electronic device with poor turn-off gain is_
88/100
A thyristor equivalent of a thyratron tube is a _
89/100
Which of the following does not cause damage of an SCR?
90/100
Which one of the following power semiconductor device has bi-directional current capability?
91/100
n advantage of a Cycloconverter is _
92/100
In single phase to single phase cycloconverter , if 𝛼 1 and 𝛼2 are the trigger angles of positive converter and negative converter , then _
93/100
A four quadrant chopper cannot be operated as _
94/100
If an AC chopper is feeding an inductive load, the firing pulse to the SCR_
95/100
A converter which can operate both in 3-pulse and 6-pulse modes is_
96/100
Which one of the following is the main advantage of SMPS over linear supply?
97/100
Among the following special function registers which is not bit addressable?
98/100
Which of the following instruction represents indexed addressing?
99/100
Which of the following 8051 interfacing peripheral acts as a programmable interrupt controller?
100/100
in 8051 microcontroller, _ register is used to control the operation of the serial port.
Result: