The dc motor, which can provide zero speed regulation at full load without any controller is

The dc motor, which can provide zero speed regulation at full load without any controller is 

(A) series (B) shunt (C) cumulative compound (D) differential compound
by

1 Answer

Answer :

The dc motor, which can provide zero speed regulation at full load without any controller is shunt 

by

Related questions

Why does the speed of a DC shunt motor decrease as the load increases?

Description : Why does the speed of a DC shunt motor decrease as the load increases?

Last Answer : Because if the load is increasing then the torque must also be increase. If not then the speed of motor will decrease.

A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated

Description : A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply voltage has to be approximately brought down to  (A) 0.75 p.u (B) 0.5 p.u (C) 0.25 p.u (D) 0.125 p.u

Last Answer : A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply voltage has to be approximately brought down to 0.5 p.u

Why shouldn’t a DC shunt motor start on the heavy load setting?

Description : Why shouldn’t a DC shunt motor start on the heavy load setting?

Last Answer : A series motor never started at no load and a shunt motor is never started at on load.

What will happen when a DC shunt motor is started with a load?

Description : What will happen when a DC shunt motor is started with a load?

Last Answer : Starting current will be very high so motor will take more current from supply. It may damage the armature winding.

To conduct load test on a dc shunt motor, it is coupled to a generator which is identical to the motor. The field

Description : To conduct load test on a dc shunt motor, it is coupled to a generator which is identical to the motor. The field of the generator is also connected to the same supply source as the motor. The armature of generator is ... value of this load resistance is  (A) 1.0 (B) 0.98 (C) 0.96 (D) 0.94

Last Answer : To conduct load test on a dc shunt motor, it is coupled to a generator which is identical to the motor. The field of the generator is also connected to the same supply source as the motor. ... obtain rated armature current in both motor and generator. The p.u value of this load resistance is 0.96

If the pole flux of a d.c. motor approaches zero, its speed will?

Description : If the pole flux of a d.c. motor approaches zero, its speed will?

Last Answer : If the pole flux of a d.c. motor approaches zero, its speed will approach infinity.

With the increase in load on a d.c. shunt motor, speed of the motor

Description : With the increase in load on a d.c. shunt motor, speed of the motor (a) increases proportionately (b) remains constant (c) increase slightly (d) reduces slightly 

Last Answer : With the increase in load on a d.c. shunt motor, speed of the motor reduces slightly.

When load is removed, .......... motor will run at the highest speed.

Description : When load is removed, .......... motor will run at the highest speed.

Last Answer : When load is removed, series motor will run at the highest speed.

If load on a d.c. shunt motor is increased, its speed is decreased due primarily to?

Description : If load on a d.c. shunt motor is increased, its speed is decreased due primarily to?

Last Answer : If load on a d.c. shunt motor is increased, its speed is decreased due primarily to decrease in back e.m.f.

Under constant load conditions, the speed of a d.c. motor is affected by?

Description : Under constant load conditions, the speed of a d.c. motor is affected by?

Last Answer : Under constant load conditions, the speed of a d.c. motor is affected by field flux.

State at least one function and the material used for the following parts of DC Motor.

Description : State at least one function and the material used for the following parts of DC Motor.

Last Answer : Part Function Material Yoke -Provides mechanical support for poles -Acts as protecting cover for machine -Provides path for magnetic flux Cast Iron OR Cast Steel Field Winding - ... Pole core  Provides mechanical support to field winding. Cast Iron OR Cast Steel

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

Under which of the following conditions is a DC motor provided with compensating winding

Description : Under which of the following conditions is a DC motor provided with compensating winding used?  1. Wide range of speed control above normal  2. Wide range of steady load variation with no speed control  3. Wide range of rapid variation in ...  (a) 1, 2 and 3 (b) 2 and 3 (c) 1 and 2 (d) 1 and 3

Last Answer : Under which of the following conditions is a DC motor provided with compensating winding used?  1. Wide range of speed control above normal  2. Wide range of steady load variation with no speed control  3. Wide range of rapid variation ...  (a) 1, 2 and 3 (b) 2 and 3 (c) 1 and 2 (d) 1 and 3

In DC motor iron losses are occurred in?

Description : In DC motor iron losses are occurred in?

Last Answer : In DC motor iron losses are occurred in the armature.

Between no-load and full-load, .......... motor develops the least torque.

Description : Between no-load and full-load, .......... motor develops the least torque.

Last Answer : series motor

If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens?

Last Answer : If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens this will make armature to take heavy current, possibly burning it.

One function of the movable cams in a drum-type motor controller is to _____________. A. regulate the speed of the motor B. maintain resistance contacts in clean condition C. insulate the operating handle D. limit the amount of load put on the motor

Description : One function of the movable cams in a drum-type motor controller is to _____________. A. regulate the speed of the motor B. maintain resistance contacts in clean condition C. insulate the operating handle D. limit the amount of load put on the motor

Last Answer : Answer: A

The d.c. series motor should never be switched on at no load because?

Description : The d.c. series motor should never be switched on at no load because?

Last Answer : The d.c. series motor should never be switched on at no load because the speed becomes dangerously high.

If the load current and flux of a d.c. motor are held constant and voltage applied ...

Description : If the load current and flux of a d.c. motor are held constant and voltage applied across its armature is increased by 10 per cent, its speed will?

Last Answer : If the load current and flux of a d.c. motor are held constant and voltage applied across its armature is increased by 10 percent, its speed will increase by about 10 percent.

D.C. motor is to a drive a load which is almost nil for certain part of the load cycle...

Description : D.C. motor is to a drive a load which is almost nil for certain part of the load cycle and peak value for short duration. We will select the?

Last Answer : D.C. motor is to a drive a load which is almost nil for certain part of the load cycle and peak value for short duration. We will select the compound motor.

D.C. motor is to drive a load which has certain minimum value for most of the time and some peak value...

Description : D.C. motor is to drive a load which has certain minimum value for most of the time and some peak value for short duration. We will select the?

Last Answer : DC motor mostly preferred is DC series motor becaus the load is continuous for a long time

Which motor should not be started on no-load ?

Last Answer : Series motor should not be started on no-load.

Autotransformer starters or compensators are sometimes used with polyphase induction motors to _____________. A. reduce the voltage applied to the motor during the starting period B. increase the voltage for 'across-the-line starting' C. provide a backup means of voltage regulation for emergency starting D. allow the voltage to be either stepped up or down, depending on the application, to ensure full torque

Description : Autotransformer starters or compensators are sometimes used with polyphase induction motors to _____________. A. reduce the voltage applied to the motor during the starting period B. increase the voltage for ' ... to be either stepped up or down, depending on the application, to ensure full torque

Last Answer : Answer: A

A cumulative dc compound motor runs at 1500 rpm. on full load. If its series field is short-circuited, its speed

Description : A cumulative dc compound motor runs at 1500 rpm. on full load. If its series field is short-circuited, its speed  (1) becomes zero (2) remains unchanged (3) increases (4) decreases

Last Answer : Increases. As it's cumulative compound motor, both series and shunt field both assist each other. If series field is short circuited, the overall field strength will decrease and atop of that ... speed is inversely proportional to field strength.  So, the speed will increase overall.

In a transformer, zero voltage regulation at full load is

Description : In a transformer, zero voltage regulation at full load is   (a)Not possible   (b) Possible at unity power factor load   (c) Possible at leading power factor load   (d) Possible at lagging power factor load

Last Answer : In a transformer, zero voltage regulation at full load is Possible at leading power factor load 

The chief advantage of Ward-Leonard system D.C. motor speed control is that is

Description : The chief advantage of Ward-Leonard system D.C. motor speed control is that is  1. Can be used even for small motors 2. has high overall efficiency at all speeds 3. Gives smooth, sensitive and wide speed control 4. Uses a flywheel to reduce fluctuations in power demand

Last Answer : The chief advantage of Ward-Leonard system D.C. motor speed control is that is Gives smooth, sensitive and wide speed control 

If the speed of a D.C. shunt motor is increased, the back e.m.f. of the motor will?

Last Answer : If the speed of a D.C. shunt motor is increased, the back e.m.f. of the motor will increase.

Identify the increasing order of voltage regulation of the following dc generators a same load :

Description : Identify the increasing order of voltage regulation of the following dc generators a same load :  (A) differential compound, shunt and under compound  (B) shunt, differential compound and ... C) under compound, shunt and differential compound  (D) shunt, under compound and differential compound

Last Answer : Identify the increasing order of voltage regulation of the following dc generators a same load : under compound, shunt and differential compound 

If the supply voltage is 220 volts 60 Hz, what is the operating voltage of the motor controller circuitry illustrated? EL-0011 A. 110 volts DC B. 110 volts AC C. 220 volts DC D. 220 volts AC

Description : If the supply voltage is 220 volts 60 Hz, what is the operating voltage of the motor controller circuitry illustrated? EL-0011 A. 110 volts DC B. 110 volts AC C. 220 volts DC D. 220 volts AC

Last Answer : Answer: D

A series wound DC motor has its armature and field connected in series with a resistor. When the motor is disconnected from its power supply, this motor will exemplify __________. A. the proper connections for across the line starting B. the proper connections for an automatic strip heater C. a reversing controller circuit D. dynamic braking

Description : A series wound DC motor has its armature and field connected in series with a resistor. When the motor is disconnected from its power supply, this motor will exemplify __________. A. the ... the proper connections for an automatic strip heater C. a reversing controller circuit D. dynamic braking

Last Answer : Answer: D

When an AC or a DC motor fails to start, the FIRST step in troubleshooting should be to check the ____________. A. motor windings for obvious opens B. motor controller leads for continuity C. fuse or circuit breaker D. motor controller leads for grounds

Description : When an AC or a DC motor fails to start, the FIRST step in troubleshooting should be to check the ____________. A. motor windings for obvious opens B. motor controller leads for continuity C. fuse or circuit breaker D. motor controller leads for grounds

Last Answer : Answer: C

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

If you hear a loud buzzing noise coming from a magnetic motor controller, you should ____________. A. assume that the motor is operating at a full load B. assume that the controller is operating normally C. notify the electrician or watch engineer of the problem D. feel the outside of the casing with your hand to see if it is hot

Description : If you hear a loud buzzing noise coming from a magnetic motor controller, you should ____________. A. assume that the motor is operating at a full load B. assume that the controller is operating normally C. ... of the problem D. feel the outside of the casing with your hand to see if it is hot

Last Answer : Answer: C

The counter EMF produced in the windings of a DC motor is 'zero' when the ____________. A. armature has just begun to turn B. armature is not turning C. motor is almost up to rated speed D. motor is at rated speed

Description : The counter EMF produced in the windings of a DC motor is 'zero' when the ____________. A. armature has just begun to turn B. armature is not turning C. motor is almost up to rated speed D. motor is at rated speed

Last Answer : Answer: B

The frequency of the rotor current in a 3 phase 50 Hz, 4 pole induction motor at full load speed is about (A) 50 Hz. (B) 20 Hz. (C) 2 Hz. (D) Zero.

Description : The frequency of the rotor current in a 3 phase 50 Hz, 4 pole induction motor at full load speed is about (A) 50 Hz. (B) 20 Hz. (C) 2 Hz. (D) Zero.

Last Answer : (C) 2 Hz.

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

A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of the machine as a motor will be (A) 800 rpm. (B) more than 800 rpm. (C) less than 800 rpm. (D) both higher or lower than 800 rpm.

Description : A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of ... . (B) more than 800 rpm. (C) less than 800 rpm. (D) both higher or lower than 800 rpm.

Last Answer : (C) less than 800 rpm.

A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s.

Description : A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be

Last Answer : A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be 474 V

The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a

Description : The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, Φ (A) directly proportional to α and Φ (B) ... proportional to α and inversely proportional to Φ (D) directly proportional to Φ and inversely proportional to α

Last Answer : The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, Φ directly proportional to α and inversely proportional to Φ

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

A transformer has negative voltage regulation when its load power factor is- (a) Zero (b) Unity (c) Leading (d) Lagging

Description : A transformer has negative voltage regulation when its load power factor is- (a) Zero (b) Unity (c) Leading (d) Lagging

Last Answer : Ans: C

51 A transformer has negative voltage regulation when its load power factor is A. Zero B. Unity C. Leading D. Lagging

Description : 51 A transformer has negative voltage regulation when its load power factor is A. Zero B. Unity C. Leading D. Lagging

Last Answer : C. leading

For a short transmission line with r/x ratio of is 1.0, the regulation will be zero when the load power factor is

Description : For a short transmission line with r/x ratio of is 1.0, the regulation will be zero when the load power factor is

Last Answer : For a short transmission line with r/x ratio of is 1.0, the regulation will be zero when the load power factor is 0.707 lead

A separately excited d.c. motor fed from single phase full converter with firing angle 60° runs at 1000 r.p.m.

Description : A separately excited d.c. motor fed from single phase full converter with firing angle 60° runs at 1000 r.p.m. If motor is connected to single phase semiconverter with the same firing angle of 60°, it would run at (a) 2000 rpm (b) 1850 rpm (c) 1500 rpm (d) 1000 rpm 

Last Answer : Ans =1500

The purpose of a trim tab is: a. To assist the pilot in initiating movement of the controls b. To zero the load on the pilot controls in the flight attitude required c. To provide feel to the controls at high speed d. To increase the effectiveness of the controls

Description : The purpose of a trim tab is: a. To assist the pilot in initiating movement of the controls b. To zero the load on the pilot controls in the flight attitude required c. To provide feel to the controls at high speed d. To increase the effectiveness of the controls

Last Answer : b. To zero the load on the pilot controls in the flight attitude required

Warning signs that cause the auditor to question management integrity must be taken seriously and pursued vigorously. Which of the following may lead the auditor to suspect management dishonesty? a. The client has been named as a defendant in a product liability suit. b. The client has experienced a decrease in revenue from increased import competition. c. A new statutory regulation making customer licenses more difficult to obtain may adversely affect the client's operations. d. The president and chief executive officer of the client corporation has held numerous meetings with the controller for the purpose of discussing accounting practices that will maximize reported profits

Description : Warning signs that cause the auditor to question management integrity must be taken seriously and pursued vigorously. Which of the following may lead the auditor to suspect management ... with the controller for the purpose of discussing accounting practices that will maximize reported profits

Last Answer : The president and chief executive officer of the client corporation has held numerous meetings with the controller for the purpose of discussing accounting practices that will maximize reported profits

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

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 speed. C. The motor will run as a generator with the proper wiring. D. Motor rotation can be reversed by reversing the leads on the starting winding.

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

The effect of carrying field excitation excessively high on a synchronous motor will result in a _____________. A. tendency for the motor to fall out of step B. tendency for the motor to overspeed C. tendency for the motor to overheat D. loss of motor speed regulation

Description : The effect of carrying field excitation excessively high on a synchronous motor will result in a _____________. A. tendency for the motor to fall out of step B. tendency for the motor to overspeed C. tendency for the motor to overheat D. loss of motor speed regulation

Last Answer : Answer: C