AP ECET 2019 (EEE) Question Paper with Answers

1/100
Superposition theorem is not applicable for ----
A) voltage calculations
B) bilateral elements
C) power calculations
D) passive elements
2/100
Which one of the following materials cannot be used for permanent magnets?
A) Alnico
B) barlum ferrite
C) Carbon-Steel
D) Iron-Cobalt alloy
3/100
For a given dielectric, with increase in temperature the ionic polarizability
A) increases
B) decreases
C) remains same
D) fluctuates
4/100
Two bulbs of 100 W/250 V and 150 W/250 V are connected in series across a supply of 250 V. The power consumed by the circuit is
A) 30 W
B) 60 W
C) 100 W
D) 250 W
5/100
Three 30Ω resistors are connected in parallel across an ideal 40 V source. What would be the equivalent resistance seen by the load connected across the circuit?
A) 0Ω
B) 10Ω
C) 20Ω
D) 30Ω
6/100
The maximum power will be transferred from a voltage source to a load when_
A) he source impedance is half that of the load impedance
B) he source impedance is equal to that of the load impedance
C) he source impedance is twice that of the load impedance
D) both source and load impedances must be zero
7/100
Which of the following is not a conducting material?
A) Copper
B) Tungstun
C) Germanium
D) Platinum
8/100
The armature of a DC machine is laminated to reduce
A) The hysterisis loss
B) Eddy current loss
C) the mass
D) the inductance
9/100
A lap wound DC machine has 400 conductors and 8 poles. The voltage induced per conductor is 2V. The machine generates a voltage of
A) 100V
B) 200V
C) 400V
D) 800V
10/100
250V DC generator is run at rated speed with no excitation. The open circuit voltage will be
A) Zero
B) About 2 to 3V
C) 100 V
D) 250V
11/100
The simplest way of shifting load from one shunt generator to the other operating in parallel is by
A) Adjustment of speeds
B) Adjustment of armature resistances
C) Adjustment of field rheostats
D) Using equalizer connections
12/100
With the increase in speed of a DC motor_
A)Both back emf as well as line current increase
B) both back emf as well as line current fall
C) back emf increases but line current falls
D) back emf falls and line current increases
13/100
The direction of rotation of a DC motor can be determined by
A) Fleming's right hand rule
B) Fleming's left hand rule
C) Lenz's law
D) Ampere law
14/100
If the applied voltage to a DC machine is 230 V then the back emf for maximum Power developed is --------- papers
A) 115V
B) 200V
C) 230V
D) 460V
15/100
In a DC series motor, the torque developed is
A) Inversely proportional to armature current
B) directly proportional to armature current
C) proportional to the square of armature current
D) proportional to the square root of the armature current
16/100
If one of the control springs of a Permanent Magnet Moving Coil ammeter is broken then, when connected it will read_
A) zero
B) half of the correct value
C) twice the correct value
D) an infinite value
17/100
The principle of operation of an LVDT is based on variation of
A) Self-Inductance
B) mutual inductance
C) Reluctance
D) Permeance
18/100
The major cause of creeping in an energy meter is
A) ver compensation for friction
B) mechanical vibrations
C) excessive voltage across the potential coil
D) stray magnetic fields
19/100
current transformer has a phase error of +3° The phase angle between primary and secondary currents is
A) 30°
B) 177°
C) 180°
D) 183°
20/100
Unit of reactive power is, -_--
A) VA
B) Watt
C) VAR
D) Ohm
21/100
A series RLC circuit will have unity power factor if operated at a frequency of
A) 1/LC
B) 1/W√LC
C) 1/w²LC
D) 1/2Ï€√LC
22/100
The form factor of sinusoidal alternating current is
A) 1
B) 0
C) 1.11
D) 1.15
23/100
If the reading of two wattmeters are equal and positive in two watt meter method, the load of in a balanced 3-phase, 3-wire circuit will be
A) Zero
B) 0.5
C) 0866
D) 1
24/100
An RLC series circuit has fi and f2 as the half power frequencies and f_o as the resonant frequency. The Q-factor of the circuit is
A) (fi+f2)/2f0
B) f1–fo/f2–f0
C) fo/f1-f_2
D) f1–f2/f0
25/100
In a transformer, zero voltage regulation at full load is
A) Not possible
B) Possible at leading power factor load
C) Possible at lagging power factor load
D) Possible at unity power factor load
26/100
The transformer efficiency at relatively light loads is quite low. This is due to
A) Small copper losses
B) small secondary output
C) High fixed loss in comparison to the output
D) Poor power factor
27/100
In order to reduce the hysterisis loss_
A) Core may be laminated
B) Silicon steel may be used as the core material
C) Core may be constructed with any permanent magnet material such as Alnico
D) Core may be impregnated with varnish
28/100
Transformers are rated in KVA instead of KW because
A) Load power factor is often not known
B) kVA is fixed where KW depends on load pf
C) total transformer loss depends on volt - Ampere
D) it has become customary
29/100
Which of the following connection of transformer will give the highest secondary voltage?
A) Delta primary, delta secondary
B) Delta primary, star secondary
C) Star primary, star secondary
D) Star primary, delta secondary
30/100
For successful parallel operation of two single phase transformers, the most essential condition is that their.
A) percentage impedances are equal
B) polarities are properly connected
C) turn-ratios are exactly equal
D) KVA ratings are equal
31/100
In an auto transformer, power is transferred through
A) Conduction process only
B) Induction process only
C) Both conduction and Induction processes
D) Mutual coupling
32/100
Distributed winding is preferred over concentrated winding as it
A) reduces noise
B) reduces the machine size
C) reduces the amount of copper required
D) improves the generated emf waveform and adds rigidity and mechanical strength to the winding
33/100
The short circuit characteristic of an alternator is
A) Always linear
B) Always non-linear
C) Always triangular
D) Always circular
34/100
The maximum possible speed at which an alternator can be driven to generate 50 Hz and 4000V is.
A) 400 rpm
B) 3600 rpm
C) 3000 rpm
D) 1500 rpm
35/100
An ideal synchronous motor has no starting torque because the
A) rotor is made up of salient poles
B) relative velocity between the stator and the rotor mmfs is zero
C) relative velocity between the stator and rotor mmfs is not zero
D) rotor winding is highly reactive
36/100
In a synchronous machine, damper windings are used to,
A) help in starting as a motor
B) run it as an induction motor
C) help in starting as a motor and to reduce hunting
D) increase efficiency
37/100
Armature reaction in a synchronous motor at rated voltage and zero power factor (lead) is
A) magnetising
B) cross-magnetising
C) both magnetising and cross-magnetising
D) demagnetising
38/100
The principle of operation of a 3-phase induction motor is almost similar to that of
A) synchronous motor
B) repulsion start induction motor
C) transformer with a shorted secondary
D) capacitor start induction motor
39/100
A three phase 6-pole. 50 Hz, induction motor is running at 5% slip. What is the speed of the motor?
A) 1850 rpm
B) 900 rpm
C) 950 rpm
D) 1000 rpm
40/100
In an induction motor under running condition, the rotor reactance per phase is ------ Its standstill phase reactance.
A) s times
B) equal to
C) 1/s times
D) (1-s) times
41/100
In a three phase induction motor, the starting torque will be maximum when
A) R2=1/X2
B) R2=X2
C) R2=X2²
D) R2=√X2
42/100
The type of single phase induction motor having the highest power factor at full load is
A) shaded pole type
B) split-phase type
C) capacitor start type
D) capacitor run type
43/100
A universal motor is one which has constant speed
A) constant output
B) capability of operating both on ac and dc
C)with comparable performance
D) maximum efficiency
44/100
Which of the following power plants is free from environment al problems?
A) Diesel engine
B) Nuclear
C) Hydroelectric
D) Steam
45/100
Diversity factor is the ratio of
A) sum of maximum demands of consumers/system maximum demand
B) maximum demand of consumers/average demand
C) demand of all consumers/average demand
D) Average demand/system maximum demand
46/100
Flat rate tariff can be charged on the basis of
A) connected load
B) units consumed
C) maximum demand
D) minimum demand
47/100
In a power plant, a reverse generating capacity, which is in operable condition and available for service, but not in operation is called the
A) spinning reverse
B) firm reverse
C) cold reverse
D) hot reverse
48/100
Advantages of the improved power factor are
A) increase in operating efficiency of the power system
B) improvement in voltage regulation
C) reduction in overall cost per unit
. D) better utilization of KW capacities of prime movers, transformers switchgear and the lines
49/100
A circuit breaker normally operates
A) when the power is to be supplied
B) when the line is to be tested
C) when the switch is to be put on
D) whenever fault occurs in the line
50/100
The RRRV depends upon the
A) type of the circuit breaker
B) capacitance of the system only
C) inductance of the system only
D) inductance and capacitance of the system
51/100
Threshold characteristics of a plain impedance relay in a complex Z plane is a
A) circle passing through origin
B) circle with the centre at the origin
C) straight line passing through the origin
D) straight line offset from the origin
52/100
Buchholz relay is
A) located in the conservator tank
B) located in the transformer tank itself
C) connected in the pipe connecting main tank of transformer and conservator
D) installed in the circuit breaker
53/100
For the protection of stator winding of an alternator against internal fault involving ground, the relay used is a
A) biased differential relay
B) directional over current relay
C) plain impedance relay
D) Buchholz relay
54/100
For a medium length transmission line.A is
A) equal to B
B) equal to C
C) equal to D
D) not equal to B,C,D
55/100
When is the Ferranti effect on long overhead lines experienced?
A) The line is lightly loaded
B) the line is heavily loaded
C) the line is fully loaded
D) The power factor is unity
56/100
Hollow conductors are used in transmission lines tO
A) reduce weight of copper
B) improve stability
C) reduce corona
D) Increases power transmission capacity
57/100
The sag of a transmission line is least affected owing to
A) weight of the conductor
B) current through the conductor
C) atmospheric temperature
D) ice deposition on the conductor
58/100
if the frequency of a transmission system is changed from 50 Hz to 100 Hz, the string efficiency.
A) will increase
B) will decrease
C) remain unchanged
D) may increase or decrease depending on the line parameters
59/100
HVDC transmission is preferred to EHV AC because
A) HVDC terminal equipment are inexpensive
B) VAR compensation is not required in HVDC system
C) system stability can be improved
D) harmonics problem is avoided
60/100
The inductance of a transmission line is minimum when_
A) GMD is high
B) GMR is high
C) both GMD and GMR are high
D) GMD is low and GMR is high
61/100
Transmission lines are transposed to
A) reduce corona loss
B) reduce skin effect
C) prevent interference with neighboring telephone lines
D) prevent short circuit between any two lines
62/100
The main criterion for selection of the size of a distributor for a radial distribution system is
A) voltage drop
B) corona loss
C) temperature rise
D) capital cost
63/100
Capacitance grading of cable means
A) use of dielectrics in different concentrations
B) introduction of capacitances at various lengths of cable to counter the effect of inductance
C) use of dielectrics of different permittivities
D) grading according to capacitance per km length of the cable
64/100
The composite system (single phase AC to DC system) has been chosen for all future track electrification in India as
A) it needs light overhead catenary
B) it needs less number of substations
C) it combines the advantages of high voltage AC distribution at 50 Hz with DC series traction motors
D) It provides flexibility in the location of substations
65/100
The maximum speed at which trains run on main line railway service is
A) 160 kmph
B) 120 kmph
C) 100 kmph
D) 200 kmph
66/100
The speed-time curve for urban service has no
A) coasting period
B) free running period
C) breaking period
D) acceleration period
67/100
Trapezoidal speed-time curve pertains to
A) main line service
B) urban service
C) suburban service
D) urban/suburban service
68/100
Specific energy consumptions becomes
A) more when distance between stops is more
B) more with the higher values of acceleration
C) more with high train resistance
D) less with the increase in crest speed
69/100
The DC series motor is most suitable for traction services but more particularly for urban/suburban services because
A) DC series motors are suitable for regenerative breaking
B) DC series motors are capable of withstanding rapid fluctuations in supply Voltage
C) DC series motors are capable of developing high torque at start
D) DC series motors are capable of withstanding temporary interruption of supply without undue rush of current
70/100
Free running and costing periods are generally long in case of
A) city service
B) suburban service
C) main line service
D) outer suburban service
71/100
Tractive effort of an electric locomotive can be increased by
A) using low output motors
B) Increasing the supply voltage
C) decreasing dead weight over the driving axles
D) using high output motors and increasing dead weight over driving axles
72/100
The earth wire should be
A) good conductor of electricity
B) mechanically strong
C) good conductor and mechanically strong
D) Mechanically strong but bad conductor of electricity
73/100
The short length of the conductor used to connect the line conductor on one side of the terminal pole to the line conductor on the other side of the pole is known as
A) Jumper
B) Petticoat
C) Guard
D) Guy
74/100
Inside the earth or pit, the earthing electrode should be placed
A) horizontally
B) vertically
C) inclined at 45°
D) in any position
75/100
The cheapest system of internal wiring is --------- wiring
A) cleat
B) casing-capping
C) CTS or TRS
D) conduit
76/100
For a NPN bipolar transistor, what is the main stream of current in the base region?
A) Drift of holes
B) Diffusion of holes
C) Drift of electrons
D) Diffusion of electrons
77/100
For a junction drain current FET in the pinch off region, as the drain voltage is increased, the drain current-------
A) becomes zero
B) abruptly decreases
C) Abruptly increased
D) Remains constant
78/100
In a centre tap full wave rectifier, 100 V is the peak voltage between the centre tap and one end of the secondary. What is the maximum voltage across the reverse biased diode?
A) 200 V
B) 141 V
C) 100 V
D) 86 V
79/100
If the differential and common mode gains of a differential amplifier are 50 and 0.2 respectively, then the CMRR will be.
A) 10
B) 49.8
C) 50.2
D) 250
80/100
An Ideal amplifier has
A) Positive feedback
B) uniform frequency response
C) Infinite voltage gain
D) responds only to signals at its input terminals
81/100
The Barkhausen criterion for sustained oscillation is given by
A) Aβ =1
B) |Aβ ≥I21
C) |Aβ|<1
D) LAβ =180°
82/100
In a Wien bridge oscillator, the positive feedback attenuation is
A) 1/3
B) 1/29
C) -29
D) 3
83/100
The binary equivalent of hexadecimal number 4F2D is
A) 0101 1111 0010 1100
B) 0100 1111 0010 1100
C) 0100 1110 0010 1101
D) 0100 1111 0010 1101
84/100
The logic function A+BC is the simplified form of which of the following?
A) AB+BC
B) A+C
C) A+B
D) (A+B)(A+C)
85/100
The AND function can be realized by using only n number of NOR gates. What is n equal to
A) 1
B) 3
C) 3
D) 5
86/100
Number of comparators required to build a 5-bit Analog to Digital converter is
A) 5
B) 11
C) 21
D) 31
87/100
A thyristor equivalent of a thyratron tube is
A) SCR
B) UJT
C) Diac
D) Triac
88/100
For an SCR, dv/dt protection is achieved through the use of
A) R-L in series with SCR
B) R-C across SCR
C) L-in series with SCR
D) R-C in series with SCR
89/100
The TRIAC is equivalent to
A) Two SCRS connected in parallel
B) Two SCRS connected in antiparrel
C) One SCR. one diode connected in parallel
D) one diode, one SCR connected in antiparallel
90/100
A Gate Turn Off (GTO) thyriostor has capacity to
A) Amplify the gate current
B) turn-off when positive current puise is given at the gate
C) Turn-off when a gate pulse is given at the gate even though it is reverse blased
D) turn-off when a negative current pulse is given at the gate
91/100
Commutation overlap in the phase-controlled AC to DC converter is due to
A) load inductance
B) harmonic content of load current
C) switching operation in the converter
D) source inductance
92/100
The advantage of using a freewheeling diode with bridge type AC/DC converter is
A) regenerative breaking
B) reliable speed control
C) improved power factor
D) reduced cost of the system
93/100
A power chopper converts
A) AC to DC
B) AC to DC
C) DC to AC
D) AC to AC
94/100
AC voltage regulators are widely used in
A) traction drives
B) fan drives
C) synchronous motor drives
D) slip power recovery scheme of slip-ring induction motor
95/100
The phase controlled rectifiers used in speed control of DC motors converts fixed AC supply voltage into output voltage
A) variable DC
B) variable AC
C) variable frequency AC
D) full rectified AC
96/100
In a UPS, the solid state switch normally transfer supply within
A) 14 ms
B) 30 ms
C) 48 ms
D) 30 s
97/100
The internal RAM memory of the 8051 is
A) 32 bytes
B) 64 bytes
C) 128 bytes
D) 256 bytes
98/100
The 8051 has -------- 16-bit counter/timers
A) 1
B) 2
C) 3
D) 4
99/100
8051 can handle, ---------- interrupt sources
A) 3
B) 4
C) 5
D) 6
100/100
The I/O ports that are used as address and data for external memory are -------
A) Ports 1 and 2
B) Ports 1 and 3
C) ports 0 and 2
D) ports 0 and 3
Result:
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