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

1 Answer

Answer :

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

Related questions

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.

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

Last Answer : The direction of rotation of three phase induction motor can be reversed by plugging i.e by changing any two out of three phases of the supply to the stator of the Induction motor terminal.

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 : 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 : 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 : 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

Last Answer : Answer: B

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

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

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 : 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

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.

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 : 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 : In order to change the direction of rotation of a D.C. motor_________. I. the field leads must be changed II. the input leads must be changed A. I only B. II only C. either I or II D. neither I or II

Last Answer : Answer: A

Description : Positive values for the rotation angle θ defines a.Counter clockwise rotations about the end points b.Counter clockwise translation about the pivot point c.Counter clockwise rotations about the pivot point d.Negative direction

Last Answer : c.Counter clockwise rotations about the pivot point

Description : What effects of the earths rotation on the direction of winds and currents is called what?

Last Answer : It's called the 'coriolis' effect.

Description : We always see the same lace of the moon, because - (1) It is smaller than the earth (2) It revolves on its axis in a direction opposite to that of the earth (3) It takes equal time for revolution ... the earth and rotation on its own axis (4) It rotates at the same speed as the earth around the sun

Last Answer : (3) It takes equal time for revolution around the earth and rotation on its own axis Explanation: It is tidal locking that causes the synchronous rotation which causes the Moon to present "just one side ... to revolve (orbit) around the Earth. So it maintains a "constant face" in our direction.

Description : We always see the same lace of the moon, because - (1) It is smaller than the earth (2) It revolves on its axis in a direction opposite to that of the earth (3) It takes equal time for revolution ... the earth and rotation on its own axis (4) It rotates at the same speed as the earth around the sun

Last Answer : (3) It takes equal time for revolution around the earth and rotation on its own axis Explanation: It is tidal locking that causes the synchronous rotation which causes the Moon to present "just one side ... to revolve (orbit) around the Earth. So it maintains a "constant face" in our direction.

Description : Which of the synchroscope illustrations depicts the appropriate direction of rotation and position for closing the circuit breaker when paralleling AC generators? EL-0053 A. A B. B C. C D. D

Last Answer : Answer: D

Description : The direction of rotation of the winch shown in the illustration is changed by reversing the _____________. EL-0102 A. direction of current through the shunt field B. polarity of voltage at 'S1' and 'S2' C. direction of current through the armature D. polarity of voltage at 'L1' and 'L2'

Last Answer : Answer: C

Description : What is the direction of rotation of rotor with respect to the rotating magnetic field?

Last Answer : Answer: Rotating Magnetic Field is set up when 3 phase ac supply is provided to the stator windings of the induction motor. Rotating Magnetic Field rotates at synchronous speed. Rotor rotates in the direction of the rotating magnetic field

Description : Why the Direction of Rotation of a TABLE Fan & CEILING Fan is different?

Last Answer : In table fan rotor is rotating part, but in ceiling fan stator is rotating part, so the direction of rotation is different. Transformer is not rotating because for rotating magnetic ... degrees where as in transformer there is no physical displacement of 120degrees hence transformer cannot rotate.

Description : The designation D or Lbefore the name of a monosaccharide (a) indicates the direction of rotation of polarized light. (b) indicates the length of the carbon chain in the carbohydrate. (c) ... the primary alcohol group. (d) indicates the position of the asymmetric carbon atoms in the carbohydrate.

Last Answer : indicates the position of the OH group on the carbon next to the primary alcohol group.

Description : What is the direction of rotation of earth on its axis ?

Last Answer : West to East

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

Last Answer : 1 and S3.

Description : How is the direction of rotation varied?

Last Answer : By changing the phase sequence (from say R-Y-B to R-B-Y)

Description : In a Doppler VOR (DVOR) the reference signal is _____, the bearing signal is ______ and the direction of rotation of the bearing signal is ______. a. AM, FM, anti-clockwise b. AM, FM, clockwise c. FM, AM, anti-clockwise d. FM, AM, clockwise

Last Answer : a. AM, FM, anti-clockwise

Description : In which direction you would extract a deciduous upper molar: A. Rotation B. Buccally C. Lingually

Last Answer : B. Buccally

Description : Gears are used for: a)changing the speed rotation b)changing direction of rotation c)changing direction of shafting d)all of the above

Last Answer : d)all of the above

Description : We always see the same face of the moon, because (1) it is smaller than the earth (2) it revolves on its axis in a direction opposite to that of the earth (3) it takes equal time for revolution around the earth and rotation on its own axis (4) it rotates at the same speed as the earth around the sun

Last Answer : it takes equal time for revolution around the earth and rotation on its own axis

Description : In a synchronous machine, if the field flux axis ahead of the armature field axis in the direction of rotation, the machine is operating as  (1) synchronous motor (2) synchronous generator (3) asynchronous motor (4) asynchronous generator

Last Answer : In a synchronous machine, if the field flux axis ahead of the armature field axis in the direction of rotation, the machine is operating as synchronous generator 

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 : Which statement is true concerning a split-phase induction motor? A. Motor rotation can be reversed without changing the windings or leads. B. Motor speed can be readily adjusted from zero to full ... proper wiring. D. Motor rotation can be reversed by reversing the leads on the starting winding.

Last Answer : Answer: D