The dc motor used for intermittent high torque loads is

The dc motor used for intermittent high torque loads is 

(1) dc series motor (2) dc shunt motor (3) differential compound motor (4) cumulative compound motor
by

1 Answer

Answer :

4 cumulative compound motor


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Related questions

Which D.C. motor will be suitable along with flywheel for intermittent light and heavy loads?

Last Answer : Cumulatively compounded D.C. motor will be suitable along with flywheel for intermittent light and heavy loads.

Why a dc series motor has a high starting torque?

Description : Why a dc series motor has a high starting torque?

Last Answer : motor

Which motor has high Starting Torque and Staring current DC motor, Induction motor or Synchronous motor?

Description : Which motor has high Starting Torque and Staring current DC motor, Induction motor or Synchronous motor?

Last Answer : DC Series motor has high starting torque. We can not start the Induction motor and Synchronous motors on load, but can not start the DC series motor without load.

Which Motor Has High Starting Torque And Staring Current Dc Motor, Induction Motor Or Synchronous Motor?

Description : Which Motor Has High Starting Torque And Staring Current Dc Motor, Induction Motor Or Synchronous Motor?

Last Answer : DC Series motor has high starting torque. We can not start the Induction motor and Synchronous motors on load, but can not start the DC series motor without load.

Which of the following is not recommended by ASME B31.3 when assembling gray cast iron flanges? a) Use high strength bolting at all times. b) Carefully align the flanges. c) Carefully control bolt torque. d) Ensure piping loads transmitted to the flanges are within design conditions.

Description : Which of the following is not recommended by ASME B31.3 when assembling gray cast iron flanges? a) Use high strength bolting at all times. b) Carefully align the flanges. c) Carefully control bolt torque. d) Ensure piping loads transmitted to the flanges are within design conditions.

Last Answer : a) Use high strength bolting at all times.

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 armature diameter at which the force acts C. maximum moment arm at the center of rotation of the armature D. perpendicular distance to its center of rotation

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

The purpose of a cage rotor winding placed on the rotor of a synchronous motor is to _____________. A. provide excitation to the DC field B. start the machine as an induction motor C. contribute extra torque at synchronous speed D. prevent the machine from falling out of step

Description : The purpose of a cage rotor winding placed on the rotor of a synchronous motor is to _____________. A. provide excitation to the DC field B. start the machine as an induction motor C. contribute extra torque at synchronous speed D. prevent the machine from falling out of step

Last Answer : Answer: B

A dc cumulatively compounded motor delivers rated load torque at rated speed. If series field is short circuited, then the armature current and speed will a) Both increases b) Both decreases c) Increases and decreases d) Decreases and increases

Description : A dc cumulatively compounded motor delivers rated load torque at rated speed. If series field is short circuited, then the armature current and speed will a) Both increases b) Both decreases c) Increases and decreases d) Decreases and increases

Last Answer : Ans: Both increases

As compared to shunt and compound DC motors, the series DC motor will have the highest torque because of its comparatively ____________ at the start. (A) Lower armature resistance. (B) Stronger series field. (C) Fewer series turns. (D) Larger armature current.

Description : As compared to shunt and compound DC motors, the series DC motor will have the highest torque because of its comparatively ____________ at the start. (A) Lower armature resistance. (B) Stronger series field. (C) Fewer series turns. (D) Larger armature current.

Last Answer : (D) Larger armature current.

The torque, in a _____________is proportional to the square of the armature current (A) DC shunt motor (B) stepper motor (C) 2-phase servomotor (D) DC series motor

Description : The torque, in a _____________is proportional to the square of the armature current (A) DC shunt motor (B) stepper motor (C) 2-phase servomotor (D) DC series motor

Last Answer : (D) DC series motor

The speed-torque characteristics of a DC series motor are approximately similar to those of the _________motor. (A) universal (B) synchronous (C) DC shunt (D) two-phase

Description : The speed-torque characteristics of a DC series motor are approximately similar to those of the _________motor. (A) universal (B) synchronous (C) DC shunt (D) two-phase

Last Answer : Ans: A Universal motor has same characteristics as DC series motor and also known as an a.c series motor.

DC motor gross torque example

Description : DC motor gross torque example

Last Answer : .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }

A DC Motor develops a torque of 150 N-m. A 10 percent reduction in the field flux causes a 50 percent

Description :  A DC Motor develops a torque of 150 N-m. A 10 percent reduction in the field flux causes a 50 percent increase in armature current. The new value of torque is: A) 102.5 N-m B) 202.5 N-m C) 172.5 N-m D) 232.5 N-m

Last Answer : T1=KIf,T2=K1.5I*0.9f T1=150Nm.  T2=T1*1.5*0.9=150*1.35=202.5Nm

In a 2 kW, 200 V, 1000 rpm. DC series motor the torque at full load was found to be 0.3 N -m. The torque at

Description : In a 2 kW, 200 V, 1000 rpm. DC series motor the torque at full load was found to be 0.3 N -m. The torque at half full load in N -m is :

Last Answer : In a 2 kW, 200 V, 1000 rpm. DC series motor the torque at full load was found to be 0.3 N -m. The torque at half full load in N -m is : 0.075

For continuously running rolling mills with intermittent loading, the most suitable DC drive is

Description : For continuously running rolling mills with intermittent loading, the most suitable DC drive is   (a) DC series motor (b) DC shunt motor (c) DC differentially compound motor (d) DC cumulatively compound motor 

Last Answer : For continuously running rolling mills with intermittent loading, the most suitable DC drive is DC cumulatively compound motor 

The loads supported by an automobile frame are……….. a) Weight of the body and Passengers. b) Torque from engine and Transmission. c) Sudden Impact from Collision d) All of the above.

Description : The loads supported by an automobile frame are……….. a) Weight of the body and Passengers. b) Torque from engine and Transmission. c) Sudden Impact from Collision d) All of the above.

Last Answer : d) All of the above.

A saturable reactor uses relatively small DC currents to control _______________. A. high frequency low power loads B. low frequency low power loads C. high frequency high power loads D. low frequency high power loads

Description : A saturable reactor uses relatively small DC currents to control _______________. A. high frequency low power loads B. low frequency low power loads C. high frequency high power loads D. low frequency high power loads

Last Answer : Answer: D

In the illustration, the component labeled 'EXC' is _______. EL-0003 A. a separate class II regulated DC generator for critical direct current loads B. a generator feeding the FLD winding through the voltage regulator. C. the controller to drive the governor for turbogenerator speed. D. the electronic driver for the switchboard metering circuits

Description : In the illustration, the component labeled 'EXC' is _______. EL-0003 A. a separate class II regulated DC generator for critical direct current loads B. a generator feeding the FLD ... to drive the governor for turbogenerator speed. D. the electronic driver for the switchboard metering circuits

Last Answer : Answer: B

Which of the following operating characteristics for DC motors is considered to give high starting torque? A. series B. shunt C. cumulative-compound D. differential-compound

Description : Which of the following operating characteristics for DC motors is considered to give high starting torque? A. series B. shunt C. cumulative-compound D. differential-compound

Last Answer : Answer: A

Which of the following conditions is most likely to occur if a single element fuse were used to replace a blown dual element fuse in a motor controller circuit? A. The fuse will blow when the motor is started. B. The fuse works, but overheats at high motor loads. C. The motor runs at reduced voltage. D. The motor runs normally.

Description : Which of the following conditions is most likely to occur if a single element fuse were used to replace a blown dual element fuse in a motor controller circuit? A. The fuse will blow when the motor ... overheats at high motor loads. C. The motor runs at reduced voltage. D. The motor runs normally.

Last Answer : Answer: A

A three phase induction motor is driving full -load torque which is independent of speed. If the line voltage...

Description : A three phase induction motor is driving full -load torque which is independent of speed. If the line voltage drops to 90% of the rated value, % increase in motor copper losses  (a) 23% (b) -18% (c) 123% (d) None of these

Last Answer : A three phase induction motor is driving full -load torque which is independent of speed. If the line voltage drops to 90% of the rated value, % increase in motor copper losses (a) 23% (b) -18% (c) 123% (d) None of these

At slip equal to infinity, the torque of a three phase induction motor is :-

Description : At slip equal to infinity, the torque of a three phase induction motor is :-  a) zero b) very small c) high d) very high

Last Answer : At slip equal to infinity, the torque of a three phase induction motor is :- zero

In a d.c. series motor, the torque developed is 20 Nm at 10A. If the load current is doubled, the new torque will be : -

Description : In a d.c. series motor, the torque developed is 20 Nm at 10A. If the load current is doubled, the new torque will be : -  a) 60 Nm b) 45 Nm c) 80 Nm d) 100 Nm

Last Answer : In a d.c. series motor, the torque developed is 20 Nm at 10A. If the load current is doubled, the new torque will be : - 80 Nm

Reduction in supply voltage by 10% will change the torque of an induction motor by

Description : Reduction in supply voltage by 10% will change the torque of an induction motor by   (a) 38% (b) 19% (c) 9.5% (d) No change 

Last Answer : Answer is (b)

Starting torque can be obtained in the case of a single phase induction motor with identical main and ...

Description : Starting torque can be obtained in the case of a single phase induction motor with identical main and auxiliary windings by connecting:  (1) A capacitor across the mains (2) A capacitor in ... with the auxiliary winding (4) Equal value capacitors in series with the main and the auxiliary windings

Last Answer : Starting torque can be obtained in the case of a single phase induction motor with identical main and auxiliary windings by connecting:  A capacitor is series with the auxiliary winding.

In an induction motor, if the rotor resistance is equal to stand-still reactance then the maximum torque is_________.

Last Answer : In an induction motor, if the rotor resistance is equal to stand-still reactance then the maximum torque is equal to starting torque.

How does the degree of DC excitation affect pull-out torque?

Description : How does the degree of DC excitation affect pull-out torque?

Last Answer : Need answer

What is the function of the interpoles installed in DC motors? A. To provide greater torque by strengthening the main field. B. To provide sparkless commutation without having to shift the brushes. C. To limit the production of counter-electromotive force. D. To limit the starting surge current.

Description : What is the function of the interpoles installed in DC motors? A. To provide greater torque by strengthening the main field. B. To provide sparkless commutation without having to shift the brushes. C. To limit the production of counter-electromotive force. D. To limit the starting surge current.

Last Answer : Answer: B

An across-the-line starter is typically used for which of the following applications? A. Reduced-current starting of large motors B. Low torque starting of small motors C. Low resistance starting of DC motors D. Full-voltage starting of motors

Description : An across-the-line starter is typically used for which of the following applications? A. Reduced-current starting of large motors B. Low torque starting of small motors C. Low resistance starting of DC motors D. Full-voltage starting of motors

Last Answer : Answer: D

The advantage(s) of the method of D.C. motor speed control shown in the illustration is/are ______________. EL-0101 A. elimination of armature starting resistor losses B. elimination of speed instability with variable loads C. the ease of reversing motor direction D. all of the above

Description : The advantage(s) of the method of D.C. motor speed control shown in the illustration is/are ______________. EL-0101 A. elimination of armature starting resistor losses B. elimination of speed instability with variable loads C. the ease of reversing motor direction D. all of the above

Last Answer : Answer: D

In the illustrated motor, roller bearings are used because __________. EL-0001 A. of their ability to absorb moderate thrust loads B. they electrically insulate the rotor from the frame reducing cross-currents C. the shafting and end bells do not require as close a tolerance to properly fit this type of bearing D. the clearance between the rotor and stator is generally as close as mechanical tolerance will permit

Description : In the illustrated motor, roller bearings are used because __________. EL-0001 A. of their ability to absorb moderate thrust loads B. they electrically insulate the rotor from the frame reducing ... clearance between the rotor and stator is generally as close as mechanical tolerance will permit

Last Answer : Answer: D

Routine A.C. motor maintenance should include periodic ______________. A. thermometer readings at normal loads to detect abnormal temperature rises B. inspection of the motor's internals for loose rotor bars or field poles C. bearing replacement each year using sealed units if available D. all of the above

Description : Routine A.C. motor maintenance should include periodic ______________. A. thermometer readings at normal loads to detect abnormal temperature rises B. inspection of the motor's internals for loose rotor bars ... C. bearing replacement each year using sealed units if available D. all of the above

Last Answer : Answer: A

Thermal overload relays are used to protect the motor against over current due to (a) short-circuits (b) heavy loads (c) grounds (d) all of the above

Description : Thermal overload relays are used to protect the motor against over current due to (a) short-circuits (b) heavy loads (c) grounds (d) all of the above

Last Answer : (b) heavy loads

In a D.C. 3-wire distributor using balancers and having unequal loads on the two sides (a) both balancers run as generators (b) both balancers run as motors (c) balancer connected to lightly- loaded side runs as a motor (d) balancer connected to heavily- loaded side runs as a motor

Description : In a D.C. 3-wire distributor using balancers and having unequal loads on the two sides (a) both balancers run as generators (b) both balancers run as motors (c) balancer connected to lightly- loaded side runs as a motor (d) balancer connected to heavily- loaded side runs as a motor

Last Answer : (c) balancer connected to lightly- loaded side runs as a motor

Describe the following energy conservation methods of electrical motor. i) By motor survey ii) By matching loads with motor rating

Description : Describe the following energy conservation methods of electrical motor. i) By motor survey ii) By matching loads with motor rating

Last Answer : Energy conservation methods of electrical motor:  1) By Motor Survey: Large industries have a massive population of LT motors. Load survey of LT motors can be taken-up methodically to ... -speed motors, eddy-current couplings, fluid couplings, and solid-state electronic variable speed drives.

Squirrel cage induction motor has a) Zero starting torque b) Very small starting torque c) Medium starting torque d) Very high starting torque

Description : Squirrel cage induction motor has a) Zero starting torque b) Very small starting torque c) Medium starting torque d) Very high starting torque

Last Answer : Ans: B

The primary function of an electric motor is to ___________. A. develop torque B. generate high voltages C. produce a magnetic field D. generate high electrical resistance

Description : The primary function of an electric motor is to ___________. A. develop torque B. generate high voltages C. produce a magnetic field D. generate high electrical resistance

Last Answer : Answer: A

A characteristic of a wound-rotor induction motor, with a high resistance rotor winding, is _____________. A. low starting torque B. high starting torque C. high speed D. low starting voltage

Description : A characteristic of a wound-rotor induction motor, with a high resistance rotor winding, is _____________. A. low starting torque B. high starting torque C. high speed D. low starting voltage

Last Answer : Answer: B

A double squirrel-cage motor is designed to have __________. A. low starting torque B. low starting current C. high starting voltage D. low starting resistance

Description : A double squirrel-cage motor is designed to have __________. A. low starting torque B. low starting current C. high starting voltage D. low starting resistance

Last Answer : Answer: B

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

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

Why is the starting torque of a capacitor start induction motor high?

Description : Why is the starting torque of a capacitor start induction motor high?

Last Answer : Ans: The capacitor C in the starting winding is so chosen that Is leads Im by 75 degree. Since the starting torque is directly proportional to Sin Ф, and it is quite high in capacitor-start induction motor.

Why is the starting torque of a resistance split-phase induction motor not high?

Description : Why is the starting torque of a resistance split-phase induction motor not high?

Last Answer : The starting torque is given as, Ts = K Im Is Sin Ф Where K = constant whose magnitude depends upon the design of the motor (i) The angle between Is and Im is small ... Im are not equal in magnitude, the rotating magnetic field is not uniform and the starting torque produced is small.

The d.c. series motor should always be started with load because (A) at no load, it will rotate at dangerously high speed. (B) it will fail to start. (C) it will not develop high starting torque. (D) all are true.

Description : The d.c. series motor should always be started with load because (A) at no load, it will rotate at dangerously high speed. (B) it will fail to start. (C) it will not develop high starting torque. (D) all are true.

Last Answer : (A) at no load, it will rotate at dangerously high speed.

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

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 

The main drawback of supplying more excess air in the combustion of fuel is the (A) Excessive power requirement of air blower (B) Enhanced sensible heat loss in the flue gas (C) Intermittent and uncontrolled combustion of the fuel (D) High exit flue gas temperature from the furnace

Description : The main drawback of supplying more excess air in the combustion of fuel is the (A) Excessive power requirement of air blower (B) Enhanced sensible heat loss in the flue gas (C) Intermittent and uncontrolled combustion of the fuel (D) High exit flue gas temperature from the furnace

Last Answer : (B) Enhanced sensible heat loss in the flue gas

Purpose of hydraulic accumulator is to (A) Ensure intermittent supply of hydraulic pressure (B) Increase the pressure and store/ accumulate it (C) Accumulate pressure to increase force (D) Generate high pressure to operate hydraulic machines like cranes, lifts, presses etc

Description : Purpose of hydraulic accumulator is to (A) Ensure intermittent supply of hydraulic pressure (B) Increase the pressure and store/ accumulate it (C) Accumulate pressure to increase force (D) Generate high pressure to operate hydraulic machines like cranes, lifts, presses etc

Last Answer : (D) Generate high pressure to operate hydraulic machines like cranes, lifts, presses etc

A patient on the dental chair has cardiac arrest. What is INCORRECT, A. Observing the vital signs and check that the air way is clear is at high importance B. Expired air has 15% O2 only, and cardiac compressions achieve 30-40% of cardiac output C. Intermittent positive pressure at the rate of 40/min will reduce the chances of cerebral hypoxia D. Intermittent positive pressure is better than mouth to mouth when it has been given at the same rate.

Description : A patient on the dental chair has cardiac arrest. What is INCORRECT, A. Observing the vital signs and check that the air way is clear is at high importance B. Expired air has 15% O2 only, ... D. Intermittent positive pressure is better than mouth to mouth when it has been given at the same rate.

Last Answer : C. Intermittent positive pressure at the rate of 40/min will reduce the chances of cerebral hypoxia

Application of DC Series Motor

Description : Application of DC Series Motor

Last Answer : 1. Electric traction 2. Cranes, 3. Passenger elevators, 4. Continuous conveyors, 5. Grinders, 6. Polishers,

If field current is decreased in shunt dc motor, the speed of the motor

Description : If field current is decreased in shunt dc motor, the speed of the motor (a) remains same. (b) increases. (c) decreases. (d) none of the above.

Last Answer : increases

What would happen if a DC motor was supplied with AC ?

Description : What would happen if a DC motor was supplied with AC ?

Last Answer : With three phase induction motor, humming and not rotate, but if single phase universal motor like air blower, home mixture, motor run on constant speed..speed variation not possible...