Why are shaded-pole motors used to drive only very small  devices?

1 Answer

Answer :

They have very weak starting torques.

Related questions

Last Answer : The range of efficiency for shaded pole motors is 5% to 35%.

Description : In the illustrated device, the part labeled '1A' _________. EL-0001 A. are start and run windings for a single phase shaded pole induction motor B. is the stator for a polyphase induction ... armature for a squirrel cage rotor motor D. are direct current shunt field windings for a universal motor

Last Answer : Answer: B

Description : Which type of AC single-phase motor will also operate on direct current? A. Split-phase B. Series-wound C. Shaded-pole D. Repulsion-start

Last Answer : Answer: B

Description : A shaded-pole motor is a ____________. A. synchronous motor B. three-phase induction motor C. compound-wound motor D. single-phase induction motor

Last Answer : Answer: D

Description : A single-phase induction motor having a relatively high starting torque, is the ___________. A. shaded pole motor B. wound-rotor motor C. capacitor-start motor D. resistance-start motor

Last Answer : Answer: C

Description : Why shaded-pole single phase induction motor does not need any special starting technique like capacitors and auxiliary winding etc.

Last Answer : Because it is inherently self started motor. The construction of the poles is such that they give a sweep to the magnetic flux and motor starts rotating.

Description : What is size of shaded-pole motor?

Last Answer : These are usually built in small fractional H.P, not exceed 1/4 H.P.

Description : what is the application of shaded pole induction motor?

Last Answer : Because of its small starting torque, it is generally used for small fans, toys, instruments, hair driers, tape recorder, advertising display, ventilators, electric clock etc.

Description : What is the principle of operation of shaded-pole induction motor?

Last Answer : A shaded-pole motor is basically a small single-phase squirrel cage motor in which the starting winding is composed of short-circuited copper ring (called shading coil) surrounding one-third of each pole ... rotating magnetic field. As a result, the rotor is set in motion due to induction principle.

Description : In which direction does a shaded pole motor run?

Last Answer : The rotor starts rotation in the direction from unshaded part to the shaded part.

Description : what do you mean by shaded pole motor?

Last Answer : These motor have projected pole with 1/3 pole part rapped with a copper strip. This portion of the pole is called shaped part of the pole because of this a revolving field is set up in the Stator and torque is developed.

Description : The direction of rotation of hysteresis motor is reversed by (A) Shift shaded pole with respect to main pole (B) Reversing supply lead (C) Either A or B (D) Neither A nor B

Last Answer : Ans: A This motor used single phase, 50Hz supply and stator has two windings. These are connected continuously from starting to running.

Description : With a neat sketch give the working of shaded pole induction motor.

Last Answer : Explanation: It has squirrel cage rotor and salient pole stator. The stator poles are shaded partially by short circuited conductor band to create the phase difference between the fluxes emerging from shaded ... rotating magnetic field in the air-gap and torque is exerted on the squirrel cage rotor.

Description : State two applications of 1) Shaded pole motor 2) Universal motor

Last Answer : (i)Applications of Shaded pole motor: 1. Small fans 2. Toy motors 3. Hair dryers 4. Ventilators 5. Electric clocks 6. Record players 7. Motorized valves 8. Gramophones 9. Photocopying ... 5. Portable Drilling Machines 6. Electric Shavers 7. Mechanical computing Machines 8. Machine Tools etc.

Description : Draw torque characteristics of shaded pole IM. State its any two applications.

Last Answer : Torque Characteristics of Shaded Pole IM: Applications of Shaded Pole Induction Motor: 1) Small Fans 2) Recording Instruments 3) Record Players 4) Gramophones 5) Toy motors 6) Photocopying machines 7) Small clocks 8) Hair dryers

Description : A shaded pole induction motor does not have the advantage of   (a) Rugged construction (b) Low initial as well as maintenance cost (c) High starting torque (d) Comparatively small starting current 

Last Answer : c. high starting torque

Last Answer : Locked rotor current of a shaded pole motor is slightly more than full load current.

Last Answer : The shaded pole motor is used for low starting torque.

Last Answer : In case of a shaded pole motor the direction of rotation of the motor is from main pole to shaded pole.

Last Answer : A shaded pole motor can be used for toys, hair dryers, circulators etc.

Last Answer : In a shaded pole single-phase motor, the revolving field is produced by the use of shading coils.

Last 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.

Last Answer : The torque produced in induction type relay (shaded pole structure) is inversely proportional to the square of the current.

Description : A portable hand-held and is very handy for determining the power consumption and power factor of individual motors and other inductive devices. a) Voltmeter and wattmeter. b) Wattmeter and power factor meter. c) Light meter and flash meter.

Last Answer : Voltmeter and wattmeter.

Description : Which of the listed motors will operate at the highest RPM, assuming that each operates at the same frequency? A. A four-pole synchronous motor under normal load. B. A four-pole induction motor under ... A six-pole synchronous motor under normal load. D. A six-pole induction motor under full load.

Last Answer : Answer: A

Description : In the construction of D.C. motors, parts of both the series and shunt fields are wound on the _____________. A. opposite main pole B. rotor core C. interpole D. same main pole

Last Answer : Answer: D

Description : Which of the following types of DC motors has its field connected in parallel with its armature? A. Counter EMF B. Shunt C. Salient pole D. Series

Last Answer : Answer: B

Description : What type of rotor is used in split-phase motors? A. Drum B. Salient pole C. Squirrel-cage D. Wound-rotor

Last Answer : Answer: C

Description : Motors, switches, voltage regulators, generators, etc., are a few examples of emi sources. What type of emi comes from these sources?

Last Answer : Man-made.

Description : How do split-phase induction motors become self-starting?

Last Answer : By using combinations of inductance and capacitance to apply out-of phase currents in starting windings.

Description : Why series motors are sometimes called universal motors?

Last Answer : They operate on either ac or dc.

Description : What are the three basic types of ac motors?

Last Answer : Series, synchronous, induction.

Description : Which of the motors for the devices listed below is fitted with an instantaneous overload relay? A. Fan B. Pump C. Winch D. Machine tool

Last Answer : Answer: C

Description : Why The Air Gap Between The Pole Pieces And The Armature Is Kept Very Small?

Last Answer : The air gap between the pole pieces and the armature is kept very small to keep the field strength at its highest value. This is due to the reason the flux lines can pass through iron very ... must be the magnetizing force to produce the required voltage hence the air gap is kept very small.

Description : Using Weber’s molecular theory of magnetism, describe the polarity of the magnetic poles produced by stroking a magnetic material from right to left with the south pole of a magnet.

Last Answer : South pole at the right, north pole at the left.

Description : A compass is located at the geographical North Pole. In which direction would its needle point?

Last Answer : To the magnetic north pole.

Description : In describing a switch by the number of positions of the actuator, what are the two possible configurations for a single pole, double-throw switch?

Last Answer : Two-position and three-position.

Description : What advantage is gained by using pole pieces with curved faces in the D’Arsonval meter movement?

Last Answer : Two-position and three-position.

Description : Salient-pole rotors may be used in alternators driven by what types of prime movers?

Last Answer : Internal combustion engines, water force and electric motors

Description : A three-phase, induction-type motor experiences an open in one phase. Which of the listed automatic protective devices will prevent the machine from being damaged? A. Overspeed trip B. Thermal overload relay C. Three-pole safety switch D. Magnetic blowout coil

Last Answer : Answer: B

Description : What causes a green plant exposed to the light, on only one side, to bend towards the source of light as it grows? (a) Light stimulates plant cells on the lighted side to grow ... Green plants need light to perform photosynthesis. (d) Green plants seek light because they are phototropic.

Last Answer : (b) Auxin accumulates on the shaded side, stimulating greater cell elongation there

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Last Answer : D)Trial

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Description : Do surplus electric motors normally not work very well?

Last Answer : Surplus electric motors do usually work very well. I am thinking that you could have accidentally broken it when you bought it. I would bring it back to the store just in case!

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