The following motor definitely has a permanent magnet rotor

The following motor definitely has a permanent magnet rotor 

(A) DC commutator motor (B) Brushless dc motor (C) Stepper motor (D) Reluctance motor
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The following motor definitely has a permanent magnet rotor Stepper motor

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Related questions

A permanent magnet stepper motor with 8 poles in stator and 6 poles in rotor will have a step angle of

Description : A permanent magnet stepper motor with 8 poles in stator and 6 poles in rotor will have a step angle of (a) 7.5° (b) 15° (c) 30° (d) 60°

Last Answer : d

The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from

Description : The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 ... .5 A from the same source will be  (A) 48.0% (B) 57.1% (C) 59.2% (D) 88.8%

Last Answer : The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 48.0%

The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated

Description : The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor ... Hz supply is  (A) 58.5 A (B) 45.0 A (C) 42.7 A (D) 55.6 A

Last Answer : The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor is connected to a 236 , V 57 Hz supply is 45.0 A 

In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then

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 ... 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

A 3-phase, 4-pole, 50Hz induction motor runs at a speed of 1440 rpm. The rotating field produced by the rotor

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

Last Answer : 0

An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW.

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

Last 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

Locked rotor current of a shaded pole motor is?

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

The rotor slots, in an induction motor, are usually not quite parallel to the shaft because it?

Last 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.

The rotor of a hysteresis motor is made of?

Last Answer : The rotor of a hysteresis motor is made of chrome steel.

In a hysteresis motor, the rotor must have?

Last Answer : In a hysteresis motor, the rotor must have retentivity.

Types of three phase induction motor rotor

Description : Types of three phase induction motor rotor

Last Answer : Types of three phase induction motor rotorSquirrel cage rotor : There are two types of three phase induction motor rotor one is squirrel cage rotor and second is wound rotor. About 80 to ... control of three phase induction motor via rotor resistance control method is possible with this rotor.

In motor a permanent magnet provides: a. Electric field b. electric flux c. magnetic field d. gravitational field

Description : In motor a permanent magnet provides: a. Electric field b. electric flux c. magnetic field d. gravitational field

Last Answer : d. gravitational field

Advantages and Disadvantages of Permanent Magnet Brushless DC (PMBLDC) Motor

Description : Advantages and Disadvantages of Permanent Magnet Brushless DC (PMBLDC) Motor

Last Answer : Advantages and Disadvantages of Permanent Magnet Brushless DC (PMBLDC) Motor

In an AC generator, direct current from a separate source is passed through the windings of the rotor _____________. A. by means of slip rings and brushes B. by means of a commutator C. by means of rotating bar magnet D. to minimize the danger of arc over

Description : In an AC generator, direct current from a separate source is passed through the windings of the rotor _____________. A. by means of slip rings and brushes B. by means of a commutator C. by means of rotating bar magnet D. to minimize the danger of arc over

Last Answer : Answer: A

Skewing of rotor bars eliminate the:

Description : Skewing of rotor bars eliminate the: (1) Effect of space harmonics (2) Entire effect of crawling (3) Magnetic noise (4) Vibration due to unequal force developed on rotor

Last Answer : Skewing of rotor bars eliminate the: Effect of space harmonics

A rotating electrical machine its self-inductances of both the stator and the rotor windings, independent of

Description : A rotating electrical machine its self-inductances of both the stator and the rotor windings, independent of the rotor position will be definitely not develop  (A) starting torque (B) synchronizing torque (C) hysteresis torque (D) reluctance torque

Last Answer : A rotating electrical machine its self-inductances of both the stator and the rotor windings, independent of the rotor position will be definitely not develop synchronizing torque

Skew of rotor bar eliminates

Description : Skew of rotor bar eliminates   1. The effect of space harmonics   2. The entire effect of crawling   3. Magnetic noise   4. Vibration due to unequal force developed on rotor 

Last Answer : It  eliminates  magnetic  noise.

In dc machines, the armature windings are placed on the rotor because of the necessity for

Description : In dc machines, the armature windings are placed on the rotor because of the necessity for  (1) electromechanical energy conversion (2) generation of voltage (3) commutation (4) development of torque

Last Answer : 3  Commutation

Is the idea of permanent magnet "free energy" generators impossible?

Description : Is the idea of permanent magnet "free energy" generators impossible?

Last Answer : answer:It's hard to say. I've tried building a few myself with no avail. I have gotten close a few times though, and that's just tinkering around. The problem with permanent magnets in a ... com/watch?v=bssBAb6EzM4&feature=related This one looks like it works, but was later revealed to be a hoax.

What does a permanent magnet repel? -Do You Know?

Description : What does a permanent magnet repel? -Do You Know?

Last Answer : answer:

Which of the following iron and steel is used to make a permanent magnet ?

Description : Which of the following iron and steel is used to make a permanent magnet ?

Last Answer : Steel is used between cast iron and steel to make permanent magnets.

Which is the most permanent strong magnet ?

Description : Which is the most permanent strong magnet ?

Last Answer : The most durable strong magnet is nickel.

What is a permanent magnet ?

Description : What is a permanent magnet ?

Last Answer : Even if a magnet is removed from the magnetic field, the magnetism does not disappear, so a permanent magnet.

When a piece of iron rod is brought near a permanent magnet for a while it becomes magnitised by?

Description : When a piece of iron rod is brought near a permanent magnet for a while it becomes magnitised by?

Last Answer : Need answer

What does a permanent magnet repel?

Description : What does a permanent magnet repel?

Last Answer : – Diamagnetic substances only

Permanent magnet is normally made of- (a) Aluminum (b) Wrought iron (c) Cast iron (d) Alnico alloys

Description : Permanent magnet is normally made of- (a) Aluminum (b) Wrought iron (c) Cast iron (d) Alnico alloys

Last Answer : Ans: C

Which of the following electric meter movements uses a stationary permanent magnet and movable coil? A. D'Arsonval B. Electrodynamometer C. Moving iron-vane D. Inclined coil iron-vane

Description : Which of the following electric meter movements uses a stationary permanent magnet and movable coil? A. D'Arsonval B. Electrodynamometer C. Moving iron-vane D. Inclined coil iron-vane

Last Answer : Answer: A

The timer element of a reverse power relay cannot be energized unless _____________. A. the power flow is the same as the tripping direction B. the power flow is the opposite to the tripping direction C. the movement of the disk is damped by a permanent magnet D. one generator is motorized

Description : The timer element of a reverse power relay cannot be energized unless _____________. A. the power flow is the same as the tripping direction B. the power flow is the opposite to the tripping direction C. the movement of the disk is damped by a permanent magnet D. one generator is motorized

Last Answer : Answer: A

The timer element of a reverse power relay cannot be energized unless _____________. A. one generator is fully motorized B. the movement of the disk is damped by a permanent magnet C. the power flow is the same as the tripping direction D. the power flow is the opposite to the tripping direction

Description : The timer element of a reverse power relay cannot be energized unless _____________. A. one generator is fully motorized B. the movement of the disk is damped by a permanent magnet C. the power flow is the same as the tripping direction D. the power flow is the opposite to the tripping direction

Last Answer : Answer: C

What does a permanent magnet repel?

Description : What does a permanent magnet repel?

Last Answer : D i a m a g n e t i c substances only

Magnetic field can be produced by using A. permanent magnet B. electric current C. temporary magnet D. both A and B

Description : Magnetic field can be produced by using A. permanent magnet B. electric current C. temporary magnet D. both A and B

Last Answer : permanent magnet

What is the difference between a temporary and a permanent magnet?

Description : What is the difference between a temporary and a permanent magnet?

Last Answer : A piece of steel or iron which keeps magnetic properties is called a permanent magnet. When piece of iron becomes magnetized when it is touched by magnet, which means magnetism has been induced in it. ... away from the magnet, it loses its magnetism. This type of magnet is called a temporary magnet.

The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields (a) meter is surrounded by strong magnetic fields (b) a soft iron shielding is used (c) a plastic shielding is provided (d) a shielding of anon-magnetic material is used

Description : The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields (a) meter is surrounded by strong magnetic fields (b) a soft ... is used (c) a plastic shielding is provided (d) a shielding of anon-magnetic material is used

Last Answer : (b) a soft iron shielding is used

What is the device, which depends on the action of a movalbe permanent magnet, in aligning itself in the resultant field produced by a fixed permanent magnet or current- carrying coils whose axes are displaced by a fixed angle?

Description : What is the device, which depends on the action of a movalbe permanent magnet, in aligning itself in the resultant field produced by a fixed permanent magnet or current- carrying coils whose axes are displaced by a fixed angle?

Last Answer : moving-magnet instrument

Permanent-magnet moving coil instrument can be used in

Description : Permanent-magnet moving coil instrument can be used in

Last Answer : dc work only

What is the reason why the scale of a permanent-magnet moving coil instrument is uniform?

Description : What is the reason why the scale of a permanent-magnet moving coil instrument is uniform?

Last Answer : because it is spring controlled

The most suitable metal for making permanent magnet is a) Iron b) Steel c) Silver d) Copper

Description : The most suitable metal for making permanent magnet is a) Iron b) Steel c) Silver d) Copper

Last Answer : a) Iron

Magnetic flux linked with a coil can be changed by using an: a. Permanent magnet b.Bar magnet c. Electromagnet d. Horseshoe magnet

Description : Magnetic flux linked with a coil can be changed by using an: a. Permanent magnet b.Bar magnet c. Electromagnet d. Horseshoe magnet

Last Answer : b.Bar magne

The coating on the plastic tape you use in your cassette players is w) diamagnetic x) paramagnetic y) ferromagnetic z) a permanent magnet

Description : The coating on the plastic tape you use in your cassette players is w) diamagnetic x) paramagnetic y) ferromagnetic z) a permanent magnet

Last Answer : ANSWER: Y -- FERROMAGNETIC

Permanent Magnet Moving Coil (PMMC) Instrument

Description : Permanent Magnet Moving Coil (PMMC) Instrument

Last Answer : Permanent Magnet Moving Coil (PMMC) Instrument

A permanent magnet moving coil instrument gives full scale deflection of 25mA when a voltage of 75mV is applied across it. Calculate: (i) Resistance of shunt required for full scale deflection of 150 A. (ii) Series resistance for full scale deflection of 500 V.

Description : A permanent magnet moving coil instrument gives full scale deflection of 25mA when a voltage of 75mV is applied across it. Calculate: (i) Resistance of shunt required for full scale deflection of 150 A. (ii) Series resistance for full scale deflection of 500 V.

Last Answer : Answer :

(i) Explain the working principle of Electrostatic and permanent magnet speaker. (ii) Compare Woofer and Tweeter.

Description : (i) Explain the working principle of Electrostatic and permanent magnet speaker. (ii) Compare Woofer and Tweeter.

Last Answer : (i) Electrostatic speaker. The voltage is applied to the central or movable plate, the signal voltage is applied to the two outside plates causes these plates to attract or repel each other. ... to minimize the impact of this resonant frequency. (ii) Compare Woofer and Tweeter.

Compare variable reluctance and permanent magnet motors.

Description : Compare variable reluctance and permanent magnet motors.

Last Answer : Variable reluctance Motor  Permanent magnet motors   The rotor is not magnetised The rotor is magnetised  High torque to inertia ratio  Low torque to inertia ratio  ... rotor has salient pole construction The rotor has mostly smooth cylindrical type of construction. 

Name the material used for :- (i) Moving coil (ii) Permanent magnet in PMMC instrument.

Description : Name the material used for :- (i) Moving coil (ii) Permanent magnet in PMMC instrument.

Last Answer : (i) Material used for Moving coil: Copper, Aluminum( some times)  (ii) Permanent magnets are made of special alloys such as :  Aluminum-Nickel-Cobalt (Alnicos)  Strontium-Iron  Neodymium-Iron-Boron  Samarium-Cobalt.

What is permanent magnet and electromagnet?

Description : What is permanent magnet and electromagnet?

Last Answer : Permanent magnet: A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. As the name suggests, a permanent magnet is 'permanent'. ... an electric current passes through the coil. If the current is interrupted, the magnetism is lost.

Write one application of each: i) Permanent Magnet ii) Electromagnet

Description : Write one application of each: i) Permanent Magnet ii) Electromagnet 

Last Answer : i) Applications of Permanent Magnet: 1) Field of DC motors 2) Tacho-generators 3) In stepper motors. 4) Field of two wheeler and car dynamo 5) In magnetic therapy 6) ... Motors, Generators, Transformers, Electromagnetic Relays, Circuit breakers, Traction, Measuring instruments, Electrical Bell etc.

A permanent magnet moving coil ammeter has a coil resistance of 99 ohm and Full Scale Deflection (FSD)

Description : A permanent magnet moving coil ammeter has a coil resistance of 99 ohm and Full Scale Deflection (FSD) current of 0.1mA. Shunt resistance is 1 ohm. Current through the meter at 0.5 F.S.D is:

Last Answer : A permanent magnet moving coil ammeter has a coil resistance of 99 ohm and Full Scale Deflection (FSD) current of 0.1mA. Shunt resistance is 1 ohm. Current through the meter at 0.5 F.S.D is: 0.05mA

Permanent magnet moving coil instruments are used for

Description : Permanent magnet moving coil instruments are used for

Last Answer : PMME are mostly used for measuring voltage and current.

A neodymium magnet is a permanent magnet made from an alloy of _________

Description : A neodymium magnet is a permanent magnet made from an alloy of _________ A) Neodymium and iron B) Neodymium, iron and iodine C) Neodymium and boron D) Neodymium, iron and boron

Last Answer : A neodymium magnet is a permanent magnet made from an alloy of Neodymium, iron and boron

The main purpose of permanent magnet motors are

Description : The main purpose of permanent magnet motors are (A) to avoid the need for field supply (B) to provide high flux density (C) to provide control over flux level (D) to facilitate kW rating

Last Answer : The main purpose of permanent magnet motors are to avoid the need for field supply