In a double squirrel cage induction motor, good starting torque is produced as (A) Large current flows through the outer high resistance winding. (B) Large current flows through the inner high ... the outer high resistance winding. (D) Large current flows through the inner low resistance winding.
Last Answer : In a double squirrel cage induction motor, good starting torque is produced as Large current flows through the outer high resistance winding.
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May 8, 2018
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anonymous

Last Answer : Capacitor start motor has high torque in starting
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133 views
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Sep 13, 2017
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anonymous

Why a dc series motor has a high starting torque?
Last Answer : motor
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86 views
1 answer
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Mar 15, 2018
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anonymous

Last Answer : Speed torque characteristic of a repulsion induction motor is similar to that of a D.C. compound motor.
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164 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : The ratio of starting torque to full-load torque is least in case of shunt motors.
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878 views
1 answer
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Mar 20, 2018
by
anonymous

The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?
Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.
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302 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The speed/load characteristics of a universal motor is same as that of D.C. series motor.
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175 views
1 answer
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Mar 20, 2018
by
anonymous

A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be
Last Answer : A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be 474 V
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1 answer
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May 8, 2018
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anonymous

Last Answer : As the load is increased the speed of D.C. shunt motor will reduce slightly.
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1 answer
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Mar 20, 2018
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anonymous

Last Answer : Buses, trains, trolleys, hoists, cranes require high starting torque and therefore make use of D.C. series motor.
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117 views
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Mar 20, 2018
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anonymous

Last Answer : If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens this will make armature to take heavy current, possibly burning it.
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158 views
1 answer
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Mar 20, 2018
by
anonymous

Why does the speed of a DC shunt motor decrease as the load increases?
Last Answer : Because if the load is increasing then the torque must also be increase. If not then the speed of motor will decrease.
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2.7k views
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Jul 5, 2019
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anonymous

Why high starting torque is required?
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64 views
0 answers
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Mar 15, 2018
by
anonymous

The torque developed by any 3-phase induction motor at 0.8 p.u. slip is (A) Full-load torque (B) unstable torque (C) starting torque (D) break down
Last Answer : The torque developed by any 3-phase induction motor at 0.8 p.u. slip is unstable torque
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Apr 28, 2018
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anonymous

Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be
Last Answer : Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be 25 N -m
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Apr 29, 2018
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anonymous

Last Answer : The armature torque of the D.C. shunt motor is proportional to armature current.
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210 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : In repulsion motor, maximum torque is developed when brush axis is at 45° electrical to the field axis.
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116 views
1 answer
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Mar 20, 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 : For starting a D.C. motor a starter is required because it limits the starting current to a safe value.
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Mar 20, 2018
by
anonymous

Last Answer : The starting winding of a single-phase motor is placed in stator.
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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

Last Answer : Starting winding of a single phase motor of a refrigerator is disconnected from the circuit by means of a magnetic relay.
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215 views
1 answer
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Mar 20, 2018
by
anonymous

How is a three phase cage induction motor self starting?
Last Answer : Any type of induction motor is self starting. Because the reason for torqe production require two flux displaced by some angle theta.If theta is constant with time then torqe will be constant;if ... torqe also pulsating. In induction motor this angle theta is not pulsating.so it is self starting
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Mar 17, 2018
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anonymous

Is induction motor is self starting?
Last Answer : Single phase induction motor is not self starting. Three phase induction motor is self starting.
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Mar 17, 2018
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anonymous

Last Answer : The wattage rating for a ceiling fan motor will be in the range 50 to 150 W .
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177 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : For constant torque drive armature voltage control speed control method is preferred.
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177 views
1 answer
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Mar 20, 2018
by
anonymous

A 40 kVA transformer has a core loss of 400 W and a full load copper loss of 800 W. The proportion of full load at maximum efficiency is
Last Answer : A 40 kVA transformer has a core loss of 400 W and a full load copper loss of 800 W. The proportion of full load at maximum efficiency is 0.707
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774 views
1 answer
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May 8, 2018
by
anonymous
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A transformer operates 24 hours day at full -load. It's full -load efficiency is : (A) equal all day efficiency (B) more than all -day efficiency (C) less than all -day efficiency (D) equal to maximum efficiency
Last Answer : A transformer operates 24 hours day at full -load. It's full -load efficiency is : equal all day efficiency
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264 views
1 answer
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Apr 30, 2018
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anonymous

Last Answer : In a level compounded D.C. generator, full load terminal voltage is equal to no-load terminal voltage.
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1 answer
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Mar 21, 2018
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anonymous

Last Answer : In over compounded generator, full load terminal voltage is more than no load terminal voltage.
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1 answer
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Mar 21, 2018
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anonymous

Last Answer : In case of a reluctance motor, when the load is increased so that it cannot maintain synchronous speed the motor will run as induction motor.
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111 views
1 answer
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Mar 20, 2018
by
anonymous

DC motor gross torque example
Last Answer : .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }
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145 views
2 answers
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Apr 24, 2020
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anonymous

Last Answer : Torque developed by a D.C. motor depends upon magnetic field, active length of the conductor, current flow through the conductors, number of conductors, radius of armature.
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638 views
1 answer
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Mar 20, 2018
by
anonymous
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Last Answer : A synchronous motor can develop synchronous torque at synchronous speed.
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1 answer
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Mar 20, 2018
by
anonymous

The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor, at rated stator supply voltage and frequency, is known as?
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106 views
0 answers
asked
Mar 20, 2018
by
anonymous

What is the maximum value of torque angle in synchronous motor?
Last Answer : The maximum value of torque angle in synchronous motor is 90 degrees electrical.
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Mar 18, 2018
by
anonymous

The effect of increasing load on a synchronous motor running with normal excitation is (A) Increase both its Ia and power factor. (B) Decrease Ia, but increase power factor. (C) Increase Ia, but decrease power factor (D) Decrease both Ia and power factor.
Last Answer : The effect of increasing load on a synchronous motor running with normal excitation is Increase Ia, but decrease power factor
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548 views
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Apr 28, 2018
by
anonymous

In synchronous motor, does the winding losses vary with load?
Last Answer : No, in the synchronous motor the winding losses do not vary with load.
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512 views
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Mar 3, 2018
by
anonymous

List different starting methods of three phase synchronous motor. Explain any one of them.
Last Answer : Different Starting Methods of Three Phase Synchronous Motor: As synchronous motor is not self starting, different methods of starting are as follows: 1) By using an Induction (Pony) motor 2) ... . The rotor gets pulled into synchronism and starts running at constant speed as a synchronous motor.
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1 answer
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May 7, 2020
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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1 answer
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Mar 20, 2018
by
anonymous

Last Answer : A centrifugal switch is used to disconnect starting winding when motor has picked up about 50 to 70 per cent of rated speed.
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1 answer
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Mar 20, 2018
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anonymous

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

A synchronous motor can be made self starting by providing?
Last Answer : A synchronous motor can be made self-starting by providing damper bar.
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131 views
1 answer
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Mar 18, 2018
by
anonymous

Why starter is required for starting an induction motor?
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114 views
0 answers
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Mar 15, 2018
by
anonymous
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Why does induction motor have high starting current?
Last Answer : In induction motor , the flux produce is quadrature to the applied voltage. Since when we are going to start motor , there is no flux present inside . So in order to lets say compensate it ... times of current to further increase flux. So that is reason for high starting current in induction motor
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143 views
2 answers
asked
Mar 15, 2018
by
anonymous

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque (1) Decreases (2) Increases (3) Remains constant (4) None of the above
Last Answer : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque Increases
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234 views
1 answer
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May 1, 2018
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anonymous

The speed of a 2-pole, 3-phase stepper motor operated by 1200 pulses/min (A) 100 rpm (B) 200 rpm (C) 400 rpm (D) 800 rpm
Last Answer : The speed of a 2-pole, 3-phase stepper motor operated by 1200 pulses/min 200 rpm
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151 views
1 answer
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Apr 28, 2018
by
anonymous
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Last Answer : In variable speed motor a weaker commutating field is needed at low speed than at high speed.
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62 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : Series motor has the poorest speed control.
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103 views
1 answer
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Mar 20, 2018
by
anonymous
