Last Answer : In capacitor start single-phase motors current in the starting winding leads the voltage.
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101 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : If the capacitor of a single-phase motor is short-circuited the motor will not start.
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104 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : In a capacitor start motor, the phase displacement between starting and running winding can be nearly 90°.
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207 views
1 answer
asked
Mar 20, 2018
by
anonymous

Explain the working of a single phase capacitor start induction motor.
Last Answer : Single phase capacitor start induction motor https://youtu.be/31lvvzU5Puc
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394 views
2 answers
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Jul 30, 2019
by
anonymous

Last Answer : To reverse the direction of rotation of a capacitor start motor while it is running we should disconnect motor from the supply till it stops then reconnect it to supply with reversed connection of main or auxiliary winding.
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131 views
1 answer
asked
Mar 20, 2018
by
anonymous

A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will?
Last Answer : A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will not start at all.
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231 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : In a capacitor start and run motors the function of the running capacitor in series with the auxiliary winding is to improve power factor.
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710 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The capacitors used in single-phase capacitor motors have no polarity marking.
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133 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : A single-phase induction motor is inherently non-self-starting with low torque.
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73 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The power factor of a single-phase induction motor is usually lagging.
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189 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : In a shaded pole single-phase motor, the revolving field is produced by the use of shading coils.
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204 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The rotor developed by a single-phase motor at starting is zero.
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89 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The repulsion-start induction-run motor is used because of high starting torque.
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89 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : In a two value capacitor motor, the capacitor used for running purposes is paper spaced oil filled type.
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162 views
1 answer
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Mar 20, 2018
by
anonymous
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Last Answer : The value of starting capacitor of a fractional horse power motor will be 300 uF .
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98 views
1 answer
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Mar 20, 2018
by
anonymous

Why is a capacitor used in a single phase motor and not in three phase motor ?
Last Answer : In 1-phase induction motor capacitor work is generate the auxiliary winding current than excite the main winding to rotor starts rotate. After rotor start rotating about 75% of their speed than auxiliary ... emf to start the motor.so,in 3-phase induction motor is self start induction motor.
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260 views
6 answers
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Sep 2, 2019
by
anonymous

In a single-phase induction motor, the operating direction is determined by the ________ A) Rotor B) Stator C) Starting circuit D) None of these
Last Answer : In a single-phase induction motor, the operating direction is determined by the Starting circuit
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128 views
1 answer
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Apr 29, 2018
by
anonymous
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The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, Φ (A) directly proportional to α and Φ (B) ... proportional to α and inversely proportional to Φ (D) directly proportional to Φ and inversely proportional to α
Last Answer : The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, Φ directly proportional to α and inversely proportional to Φ
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150 views
1 answer
asked
Apr 28, 2018
by
anonymous

In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then (A) the flux is constant (B) the flux first decreases and then increases in ... increases and decreases in the opposite direction with the same magnitude (D) current flows through the rotor
Last Answer : In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then the flux first decreases and then increases in the same direction
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95 views
1 answer
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Apr 28, 2018
by
anonymous

Last Answer : The starting winding of a single-phase motor is placed in stator.
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115 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : If starting winding of a single-phase induction motor is left in the circuit, it will draw excessive current and overheat.
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234 views
1 answer
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Mar 20, 2018
by
anonymous

Why synchronous motor Cannot start itself?
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75 views
0 answers
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Mar 15, 2018
by
anonymous

Which type of starter is used to start the DC motor?
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77 views
0 answers
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Mar 15, 2018
by
anonymous
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Last Answer : If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then Electrolytic capacitor will, in all probability, suffer break down.
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169 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : Two-value capacitor motor finds increased application as compressor motor in small home air-conditioners because it has low starting as well as running currents at relatively high power factor.
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74 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In a ceiling fan employing capacitor run motor secondary winding surrounds the primary winding.
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101 views
1 answer
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Mar 20, 2018
by
anonymous

Can we use the synchronous motor as the synchronous capacitor?
Last Answer : Yes, we can use the synchronous motor as the synchronous capacitor when the synchrnous motor is overexcited.
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91 views
1 answer
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Mar 18, 2018
by
anonymous

Ratio of the rotor reactance X to the rotor resistance R for a two-phase servo motor (A) is equal to that of a normal induction motor (B) is less than that of a normal induction motor (C) ... than that of a normal induction motor (D) may be less or greater than that of a normal induction motor
Last Answer : C
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582 views
2 answers
asked
Apr 28, 2018
by
anonymous

I got some grapic drawing questions guys and I need to see the answers immediately.Stator voltage curve for each four different start up methods.
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258 views
0 answers

A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is
Last Answer : A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is 36 Ohm
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331 views
1 answer
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May 3, 2018
by
anonymous

The normal value of the armature resistance of a d.c. motor is?
Last Answer : The normal value of the armature resistance of a d.c. motor is 0.5.
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2.9k views
1 answer
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Mar 26, 2018
by
anonymous

Last Answer : The starting resistance of a D.C. motor is generally low.
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169 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : Single phase induction motor usually operates on 0.6 power factor lagging.
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126 views
1 answer
asked
Mar 20, 2018
by
anonymous

The running winding of a single phase motor on testing with meggar is found to be ground. Most probable location of the ground will be?
Last Answer : The running winding of a single phase motor on testing with meggar is found to be ground. Most probable location of the ground will be at the slot edge where coil enters or comes out of the slot.
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116 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In a single phase motor the centrifugal switch disconnects auxiliary winding of the motor.
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269 views
1 answer
asked
Mar 20, 2018
by
anonymous

Single-phase mid-point controlled rectifier with RL load
Last Answer : Single-phase mid-point controlled rectifier with RL load : The circuit configuration of single-phase midpoint controlled rectifier is shown in the figure. During positive half-cycle of ... some part of next positive half-cycle of voltage with reversed polarity can appear across load.
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209 views
1 answer
asked
Oct 13, 2019
by
anonymous

Single-phase Midpoint controlled rectifier with Resistive load
Last Answer : Single-phase Midpoint controlled rectifier with Resistive load: 1) During positive half cycle of AC supply, a is positive with respect to b , this makes T1 forward biased and T2 is reverse ... voltage reverses the polarity and T2 is turned off. The operation is as shown in waveforms.
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612 views
1 answer
asked
Oct 13, 2019
by
anonymous

When the firing angle a of a single-phase, fully controlled rectifier feeding constant direct current into a load is 30°, the displacement power factor of the rectifier is
Last Answer : When the firing angle a of a single-phase, fully controlled rectifier feeding constant direct current into a load is 30°, the displacement power factor of the rectifier is √3/2
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1.4k views
1 answer
asked
Apr 29, 2018
by
anonymous

An additional condition for parallel operation of three-phase transformers over single-phase transformers is that
Last Answer : An additional condition for parallel operation of three-phase transformers over single-phase transformers is that the transformers should belong to the same vector group
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144 views
1 answer
asked
Apr 29, 2018
by
anonymous

A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is (A) 4.5 V (B) 6.75 V (C) 9 V (D) 13.5 V
Last Answer : A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is 9 V
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182 views
1 answer
asked
Apr 28, 2018
by
anonymous

In a 230 V, 50 Hz single-phase SCR bridge converter operating at a firing delay angle, α and with large R-L load, the input source current is (A) sinusoidal current (B) constant dc current (C) continuous rectangular pulses (D) alternating rectangular pulses
Last Answer : In a 230 V, 50 Hz single-phase SCR bridge converter operating at a firing delay angle, α and with large R-L load, the input source current is alternating rectangular pulses
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177 views
1 answer
asked
Apr 28, 2018
by
anonymous

The sequence components of current of a single-phase load connected to a 3-phase system are (A) equal positive and negative sequence components (B) equal positive, negative and zero sequence components (C) vector sum of sequence currents is zero (D) algebraic sum of sequence currents is zero
Last Answer : The sequence components of current of a single-phase load connected to a 3-phase system are equal positive, negative and zero sequence components
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478 views
1 answer
asked
Apr 28, 2018
by
anonymous

A 230 V/460 V single-phase transformer operating at 20 A and unity power factor has primary referred resistance of 0.2 Ω and reactance of 0.5 Ω. The approximate primary induced emf is (A) 216 V (B) 226 V (C) 234 V (D) 236 V
Last Answer : A 230 V/460 V single-phase transformer operating at 20 A and unity power factor has primary referred resistance of 0.2 Ω and reactance of 0.5 Ω. The approximate primary induced emf is 226 V
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139 views
1 answer
asked
Apr 28, 2018
by
anonymous

In a single-phase transformer, the magnetizing current is (A) in phase with the no-load current (B) in quadrature with the no-load current (C) the product of no-load current and power factor (D) in phase with the flux in the core
Last Answer : In a single-phase transformer, the magnetizing current is in phase with the flux in the core
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86 views
1 answer
asked
Apr 28, 2018
by
anonymous

The number of poles in a phase induction motor at 50 Hz and running at 1500 rpm will be?
Last Answer : The number of poles in a phase induction motor at 50 Hz and running at 1500 rpm will be 4.
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143 views
1 answer
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Mar 26, 2018
by
anonymous

Last Answer : In split-phase motor auxiliary winding is of thin wire placed at the top of the slots.
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72 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : Direction of rotation of a split phase motor can be reversed by reversing the connection of either running winding or starting winding.
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357 views
1 answer
asked
Mar 20, 2018
by
anonymous
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Last Answer : In a split phase motor the starting winding is connected through a centrifugal switch.
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117 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In a split phase motor, the running winding should have low resistance and high inductance.
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99 views
1 answer
asked
Mar 20, 2018
by
anonymous

A 3 micro Faraday capacitor is connected closing a switch to a supply of 100 V through 1 milli ohm series resistance. Calculate 1 the time constant 2 initial charging current 3 the initial rate of ... second,after the switch has been closed 5 the time taken for the capacitor to be fully charged.
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98 views
0 answers
asked
Aug 13, 2019
by
anonymous
