Answer :
A single-phase induction motor is inherently non-self-starting with low torque.
asked
Mar 20, 2018
by
anonymous
Description : A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because?
Answer :
A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because stator supply is not required to produce magnetic field.
asked
Mar 20, 2018
by
anonymous
Answer :
An induction motor has relatively high power factor at near full load.
asked
Mar 20, 2018
by
anonymous
Description : At which time power factor of the induction motor is low?
Answer :
The power factor of the inducction motor is low at the time of starting as compare to while the induction motor is running.
asked
Mar 3, 2018
by
anonymous
Description : In a single-phase induction motor, the operating direction is determined by the ________ A) Rotor B) Stator C) Starting circuit D) None of these
Answer :
In a single-phase induction motor, the operating direction is determined by the Starting circuit
asked
Apr 29, 2018
by
anonymous
Description : 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 the same direction (C) the flux increases and decreases in the opposite direction with the same magnitude (D) current flows through the rotor
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
asked
Apr 28, 2018
by
anonymous
Answer :
If starting winding of a single-phase induction motor is left in the circuit, it will draw excessive current and overheat.
asked
Mar 20, 2018
by
anonymous
Description : Power factor of an inductive circuit is usually improved by connecting capacitor to it in?
Answer :
Power factor of an inductive circuit is usually improved by connecting capacitor to it in parallel.
asked
Mar 25, 2018
by
anonymous
Answer :
Single phase induction motor usually operates on 0.6 power factor lagging.
asked
Mar 20, 2018
by
anonymous
Answer :
When a D.C. series motor is connected to A.C. supply, the power factor will be low because of high inductance of field and armature circuits.
asked
Mar 20, 2018
by
anonymous
Description : 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?
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.
asked
Mar 20, 2018
by
anonymous
Answer :
In a shaded pole motor, the shading coil usually consist of a single turn of heavy copper wire which is short-circuited and carries only induced current.
asked
Mar 20, 2018
by
anonymous
Answer :
In a capacitor start single-phase motor, when capacitor is replaced by a resistance motor will continue to run in same direction.
asked
Mar 20, 2018
by
anonymous
Answer :
In a shaded pole single-phase motor, the revolving field is produced by the use of shading coils.
asked
Mar 20, 2018
by
anonymous
Answer :
The rotor developed by a single-phase motor at starting is zero.
asked
Mar 20, 2018
by
anonymous
Answer :
If the capacitor of a single-phase motor is short-circuited the motor will not start.
asked
Mar 20, 2018
by
anonymous
Description : Explain energy conservation technique “by improving power quality” for induction motor.
Answer :
Energy conservation method in induction motor by improving power quality: Electrical energy can be conserved by improving the power quality. It can be achieved by avoiding voltage unbalance, maintaining ... losses can be minimized by using harmonic filter thus reducing the harmonics in the system.
asked
Sep 22, 2018
by
anonymous
Description : If the load of the normally excited synchronous motor is increased the power factor will?
Answer :
If the load of the normally excited synchronous motor is increased the power factor will become lagging.
asked
Mar 18, 2018
by
anonymous
Description : The synchronous motor which works on leading power factor and does not drive any mechanical load is called?
Answer :
The synchronous motor which works on leading power factor and does not drive any mechanical load is called synchronous condenser.
asked
Mar 18, 2018
by
anonymous
Description : If the field of synchronous motor is under excited, power factor will be?
Answer :
If the field of synchronous motor is under excited, power factor will be lagging.
asked
Mar 18, 2018
by
anonymous
Description : How can we improve power factor using synchronous motor?
asked
Mar 15, 2018
by
anonymous
Answer :
Yes, we can make the power factor of synchronous motor leading by adjusting its excitation.
asked
Mar 6, 2018
by
anonymous
Description : The number of poles in a phase induction motor at 50 Hz and running at 1500 rpm will be?
Answer :
The number of poles in a phase induction motor at 50 Hz and running at 1500 rpm will be 4.
asked
Mar 26, 2018
by
anonymous
Description : Explain the working of a single phase capacitor start induction motor.
Answer :
Single phase capacitor start induction motor https://youtu.be/31lvvzU5Puc
asked
Jul 30, 2019
by
anonymous
Description : What is the slip (as a percentage) when a 6 pole single phase induction motor operating on 220 V and 60 Hz is rotating at speed of 1140 rpm? A) 60% B) 5% C) 10% D) None of these
Answer :
What is the slip (as a percentage) when a 6 pole single phase induction motor operating on 220 V and 60 Hz is rotating at speed of 1140 rpm? A) 60% B) 5% C) 10% D) None of these
asked
Apr 29, 2018
by
anonymous
Answer :
Reason is kinetic energy
asked
Mar 20, 2018
by
anonymous
Answer :
If a single phase induction motor runs slower than normal, the most likely defect is worn bearings.
asked
Mar 20, 2018
by
anonymous
Description : How does a single phase induction motor work?
Answer :
As we know that single phase induction is not self started because for self started we require atleast two revolving field but single phase induction motor has only one. So we provide extra ... 1phase IM classified as split phase IM, capacitor start capacitor run, capacitor start induction run.
asked
Mar 17, 2018
by
anonymous
Description : explain the working of single phase induction motor.
Answer :
Stator has two winding namely main winding and auxiliary winding.when single phase ac supply is given to the motor,its produces alternating field.this field cut by a cage rotor.so some emf ... due to this emf,rotor flux produced.the interaction between two fluxes produce torque.so rotor rotates.
asked
Oct 24, 2017
by
anonymous
Answer :
Capacitor start motor has high torque in starting
asked
Sep 13, 2017
by
anonymous
Description : Single Phase Induction Motor
Answer :
Single Phase Induction Motor Single phase induction motor is mostly used in home, office, shop and many single phase appliances like pumps, ... torque and silent operation. It is uses where silent operation is required.
Answer :
In a A.C. series motor armature coils are usually connected to commutator through resistance.
asked
Mar 20, 2018
by
anonymous
Answer :
The efficiency of a properly designed synchronous motor will usually fall in range 85 to 95%.
asked
Mar 20, 2018
by
anonymous
Description : 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) inversely proportional to α and Φ (C) directly proportional to α and inversely proportional to Φ (D) directly proportional to Φ and inversely proportional to α
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
asked
Apr 28, 2018
by
anonymous
Answer :
The starting winding of a single-phase motor is placed in stator.
asked
Mar 20, 2018
by
anonymous
Description : What is the power factor when a single phase watt meter operating on 200 V and 5 A for 5 hours makes 2016 revolutions and the meter constant in revolution is 420? A) 0.04 B) 1.04 C) 0.96 D) None of these
Answer :
What is the power factor when a single phase watt meter operating on 200 V and 5 A for 5 hours makes 2016 revolutions and the meter constant in revolution is 420? A) 0.04 B) 1.04 C) 0.96 D) None of these
asked
Apr 29, 2018
by
anonymous
Answer :
The power factor of a single phase load can be calculated if the instruments available are three ammeters or three voltmeters.
asked
Mar 21, 2018
by
anonymous
Answer :
In a single phase power factor meter the phase difference between the currents in the two pressure coils is exactly 90°.
asked
Mar 21, 2018
by
anonymous
Answer :
The two pressure coils of a single phase power factor meter have the same dimensions and the same number of turns.
asked
Mar 21, 2018
by
anonymous
Answer :
The repulsion-start induction-run motor is used because of high starting torque.
asked
Mar 20, 2018
by
anonymous
Answer :
The rotor slots, in an induction motor, are usually not quite parallel to the shaft because it helps in reducing the tendency of the rotor teeth to remain under the stator teeth.
asked
Mar 20, 2018
by
anonymous
Description : 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
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
asked
May 1, 2018
by
anonymous
Description : 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
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
asked
Apr 29, 2018
by
anonymous
Description : A 400 V, 50 Hz three-phase induction motor rotates at 1440 rpm on full -load. The motor is wound for
Answer :
A 400 V, 50 Hz three-phase induction motor rotates at 1440 rpm on full -load. The motor is wound for 4 poles
asked
Apr 29, 2018
by
anonymous
Description : In a split-phase induction motor, the resistance/reactance ratios of windings are such that (A) current in the auxiliary winding leads the current in the main winding (B) current in the auxiliary winding lags the current in the main winding (C) both windings develop the same starting torque (D) both windings develop high starting current
Answer :
In a split-phase induction motor, the resistance/reactance ratios of windings are such that current in the auxiliary winding leads the current in the main winding
asked
Apr 28, 2018
by
anonymous
Description : A 3-phase, 4-pole, 50Hz induction motor runs at a speed of 1440 rpm. The rotating field produced by the rotor rotates at a speed of ________ rpm with respect to stator field. (A) 1500 (B) 0 (C) 1440 (D) 60
Answer :
0
asked
Apr 28, 2018
by
anonymous
Description : An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW. Its rotor input is (A) 5.06 kW (B) 0.3 kW (C) 100 kW (D) 83.33 kW
Answer :
An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW. Its rotor input is 83.33 kW
asked
Apr 28, 2018
by
anonymous
Description : In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an external resistance in the rotor circuit and the slip is 0.15. If the rotor winding resistance per phase is 0.2 Ω, the external resistance is (A) 0.2 Ω (B) 0.3 Ω (C) 0.4 Ω (D) 0.5 Ω
Answer :
In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an external resistance in the rotor circuit and the slip is 0.15. If the rotor winding resistance per phase is 0.2 Ω, the external resistance is 0.3 Ω
asked
Apr 28, 2018
by
anonymous
Description : How is a three phase cage induction motor self starting?
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
asked
Mar 17, 2018
by
anonymous
Description : Explain with neat circuit diagrams the procedures to perform no load and blocked rotor tests on three phase induction motor.
asked
Apr 16, 2020
by
anonymous