What factors determine the direction of rotation in a dc  motor?

1 Answer

Answer :

Direction of armature current, and direction of magnetic flux in  field.

Related questions

Description : If the connections for the field and the armature on a DC motor are reversed, _____________. A. the motor will run as a generator B. the motor will not run C. the direction of rotation will be the same D. the direction of rotation will be reversed

Last Answer : Answer: C

Description : Which of the listed conditions will occur if the polarity of the field poles and the direction of current to the brushes of a DC motor were both reversed? A. The motor would not start. ... direction of rotation of the armature would be unchanged. D. The field pole windings would become overheated.

Last Answer : Answer: C

Description : The direction of rotation of a DC propulsion motor can be changed by reversing the _____________. A. brush holder position B. polarity of the field poles C. brush staggered order D. motor interpole connections

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Description : If you reverse both the field and the armature connections to a DC propulsion motor, _____________. A. the direction of motor rotation will change B. the brushes will become overheated C. a magnetic lock will occur in the motor D. the direction of motor rotation will remain the same

Last Answer : Answer: D

Description : The direction of rotation of a DC propulsion motor can be reversed by __________. A. reversing the field connections B. reversing the field and the armature connections C. wiring the field and armature in parallel D. wiring the field and armature in series

Last Answer : Answer: A

Description : Which of the following statements describes what will happen when both the polarity of the field poles, and the direction of current to the brushes of a DC motor are reversed? A. The motor will ... of rotation of the armature will remain the same. D. The field pole windings will become overheated.

Last Answer : Answer: C

Description : Armature reaction in a dc motor causes a shift of the neutral plane in which direction?

Last Answer : Opposite the rotation.

Description : In a dc motor that must be able to rotate in both directions, how is the direction changed?

Last Answer : By reversing either field or armature connections

Description : What two receiver leads are reversed to reverse the rotor's direction of rotation?

Last Answer : 1 and S3.

Description : When 220V dc shunt alternator generating the voltage at rated value. If direction of rotation is reversed, then alternator will a) Build up its voltage with same polarity b) Build up its voltage with opposite polarity c) No build up of voltage d) None

Last Answer : Ans: No build up of voltage

Description : The torque produced by a DC motor armature is the product of the force acting at the armature surface multiplied by _____________. A. work done by the armature in one revolution B. effective ... arm at the center of rotation of the armature D. perpendicular distance to its center of rotation

Last Answer : Answer: D

Description : If the three-phase motor, shown in the illustrated schematic diagram, is running in the forward direction, which of the following actions must occur before the motor will reverse rotation? EL-0011 A. Normally-closed ... 'L1' and 'L3' must be interchanged via the 'R' contacts. D. All of the above.

Last Answer : Answer: C

Description : The direction of propeller shaft rotation in a turbo-electric synchronous propulsion drive motor is changed by reversing the _____________. A. polarity of the propulsion motor B. polarity of the propulsion generator C. phase sequence of power to the motor D. phase sequence of power to the generator

Last Answer : Answer: C

Description : As shown in the illustration, the D.C. motor's direction of rotation in changed by changing the _________________. EL-0101 A. polarity of the generator field B. direction of three-phase motor rotation C. direction of generator rotation D. polarity of the motor field

Last Answer : Answer: A

Description : Relative to the direction of rotation, a D.C. motor commutating pole has the same polarity as the _____________. A. main pole following B. interpole following C. main pole preceding D. interpole preceding

Last Answer : Answer: C

Description : Reversing any two of the three rotor leads on a wound-rotor induction motor will _____________. A. increase motor performance B. decrease motor performance C. reverse the motor rotation D. have no effect on the direction of rotation or motor performance

Last Answer : Answer: D

Description : The direction of rotation of an induction motor is ________. A. opposite the rotating field direction B. the same as the direction of the rotating field C. determined by the number of poles D. determined by the staggering of the brushes

Last Answer : Answer: B

Description : How can the direction of rotation of an AC motor be reversed?*

Last Answer : By interchanging any two supply lines.

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 : To reverse the direction of rotation of a three-phase AC induction motor, do one of the following: w) reverse any two of the three-phase connections x) change the frequency of the applied AC power y) operate the motor below the stall torque at very high slip z) none of the above

Last Answer : ANSWER: W -- REVERSE ANY TWO OF THE THREE-PHASE CONNECTIONS 

Description : How will you change the direction of rotation of a d.c.motor?

Last Answer : (i) By reversing direction of only Armature current. (ii) By reversing the direction of only field current.

Description : The direction of rotation of a 3-phase induction motor is clockwise when it is supplied with 3-phase sinusoidal voltage having phase sequence A-B-C. For counter clockwise rotation of the motor, the phase sequence of the power supply should be  (A) B-C-A (B) C-A-B (C) A-C-B (D) B-C-A or C-A-B

Last Answer : The direction of rotation of a 3-phase induction motor is clockwise when it is supplied with 3-phase sinusoidal voltage having phase sequence A-B-C. For counter clockwise rotation of the motor, the phase sequence of the power supply should be  A-C-B 

Description : The direction of rotation of an inverter fed 3-phase ac motor is reversed by (A) a mechanical reversing switch (B) reversing the input dc link voltage (C) operating the inverter as a rectifier (D) changing the sequence of switching

Last Answer : The direction of rotation of an inverter fed 3-phase ac motor is reversed by changing the sequence of switching

Description : Direction of rotation of three phase induction motor can be reversed by   (a) interchanging connections of any two phases (b) disconnecting any one phase (c) (a) and (b) both (d) None of the above 

Last Answer : The direction of rotation of 3-phase induction motor is reversed by Changing the phase sequence of supply.  OR  The direction of rotation of 3-phase induction motor is reversed by inter-changing any two phase connections of motor terminals with supply terminals.

Last Answer : The direction of rotation of a D.C. series motor can be changed by interchanging field terminals.

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.

Last Answer : The direction of rotation of universal motor can be reversed the by reversing the flow of current through either armature winding or field winding.

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Last Answer : Direction of rotation of a split phase motor can be reversed by reversing the connection of either running winding or starting winding.

Last Answer : The direction of rotation of an hysteresis motor is determined by position of shaded pole with respect to main pole.

Last Answer : In repulsion motor direction of rotation of motor is the same as that of brush shift.

Description : How can we reverse the direction of rotation of synchronous motor?

Last Answer : By reversing supply phase sequence we can reverse the direction of rotation of synchronous motor.

Description : how can we reverse the direction of rotation of three phase induction motor ?

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