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

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 
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1 Answer

Answer :

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

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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.

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.

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

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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.

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.

A shunt d.c. motor works on a.c. mains?

Description : A shunt d.c. motor works on a.c. mains?

Last Answer : A shunt d.c. motor works on a.c. mains unsatisfactorily.

A 220 V shunt motor develops a torque of 54 N-m at armature current of 10 A. The torque produced when...

Description : A 220 V shunt motor develops a torque of 54 N-m at armature current of 10 A. The torque produced when the armature current is 20 A, is?

Last Answer : Armature torque, Ta=PØZIa/2πA So Ta1/Ta2=Ia1/Ia2 Ta2=Ta1*Ia2/Ia1        =54*20/10         =108

Unlike a shunt motor, it is difficult for a series motor to stall under heavy loading because?

Description : Unlike a shunt motor, it is difficult for a series motor to stall under heavy loading because?

Last Answer : Unlike a shunt motor, it is difficult for a series motor to stall under heavy loading because it develops high overload torque.

As compared to shunt and compound motors, series motor has the highest torque...

Description : As compared to shunt and compound motors, series motor has the highest torque because of its comparatively .......... at the start.

Last Answer : As compared to shunt and compound motors, series motor has the highest torque because of its comparatively stronger series field at the start.

A d.c. shunt motor is found suitable to drive fans because they require?

Description : A d.c. shunt motor is found suitable to drive fans because they require?

Last Answer : A d.c. shunt motor is found suitable to drive fans because they require small torque at start up, large torque at high speeds.

If the field circuit of a loaded shunt motor is suddenly opened?

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Last Answer : If the field circuit of a loaded shunt motor is suddenly opened circuit breaker or fuse will open the circuit before too much damage is done to the motor.

In a manual shunt motor starter?

Last Answer : In a manual shunt motor starter over load relay is connected in series and no volt relay in parallel with the load.

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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

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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.

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.

An increase in the amount of current flow through the armature of a shunt motor is the final result of a/an _____________. A. increase in the load on the motor B. decrease in the load on the motor C. increase in counter EMF D. decrease in armature torque

Description : An increase in the amount of current flow through the armature of a shunt motor is the final result of a/an _____________. A. increase in the load on the motor B. decrease in the load on the motor C. increase in counter EMF D. decrease in armature torque

Last Answer : Answer: A

As load is added to a shunt motor, the motor will _________. A. speed up B. continue to operate at the same speed C. slow down slightly D. stop

Description : As load is added to a shunt motor, the motor will _________. A. speed up B. continue to operate at the same speed C. slow down slightly D. stop

Last Answer : Answer: C

A d.c. shunt motor runs at no load speed of 1140 r.p.m. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full load speed in r.p.m. is (A) 1080 (B) 1203 (C) 1000 (D) 1200

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Last Answer : (A) 1080

The speed of a d.c. shunt motor at no-load is (A) 5 to 10% (B) 15 to 20% (C) 25 to 30% (D) 35 to 40% higher than its speed at rated load.

Description : The speed of a d.c. shunt motor at no-load is (A) 5 to 10% (B) 15 to 20% (C) 25 to 30% (D) 35 to 40% higher than its speed at rated load.

Last Answer : (A) 5 to 10%

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

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The no load speed of a d.c. shunt motor is 1140 rpm. At full load, the armature reaction weakens the main...

Description : The no load speed of a d.c. shunt motor is 1140 rpm. At full load, the armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full load speed in rpm will be: (A) 1080 (B) 1203 (C) 1000 (D) 1200

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As the load is increased the speed of D.C. shunt motor will?

Last Answer : As the load is increased the speed of D.C. shunt motor will reduce slightly.

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Last Answer : The speed of a D.C. shunt motor more than its full-load speed can be obtained by decreasing the field current.

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

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Last Answer : series motor

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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.

D.C. shunt motors are used for driving?

Last Answer : D.C. shunt motors are used for driving machine tools.

Neglecting saturation, if current taken by a series motor is increased from 10 A to 12 A, the percentage increase...

Description : Neglecting saturation, if current taken by a series motor is increased from 10 A to 12 A, the percentage increase in its torque is ........ percent

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

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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.

It is possible to increase the field flux and, at the same time, increase the speed...

Description : It is possible to increase the field flux and, at the same time, increase the speed of a d.c. motor provided its .......... is held constant.

Last Answer : It is possible to increase the field flux and, at the same time, increase the speed of a d.c. motor provided its armature current is held constant.

An open armature connection in a DC propulsion motor could be caused by ____________. A. low-load operation B. clogged ventilation ducts C. sparking at the brushes D. a grounded shunt field coil

Description : An open armature connection in a DC propulsion motor could be caused by ____________. A. low-load operation B. clogged ventilation ducts C. sparking at the brushes D. a grounded shunt field coil

Last Answer : Answer: B

Regenerative braking (A) Can be used for stopping a motor. (B) Cannot be easily applied to DC series motors. (C) Can be easily applied to DC shunt motors (D) Cannot be used when motor load has overhauling characteristics.

Description : Regenerative braking (A) Can be used for stopping a motor. (B) Cannot be easily applied to DC series motors. (C) Can be easily applied to DC shunt motors (D) Cannot be used when motor load has overhauling characteristics.

Last Answer : Ans: B Because reversal of Ia would also mean reversal of field and hence of Eb

If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens?

Last Answer : If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens this will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses.

If a unloaded shunt motor's field were weakened by rheostat resistance or by an open circuit, the motor would _________. A. overspeed due to reduced CEMF B. stop because of low flux C. continue to run at base speed D. slow down and overheat

Description : If a unloaded shunt motor's field were weakened by rheostat resistance or by an open circuit, the motor would _________. A. overspeed due to reduced CEMF B. stop because of low flux C. continue to run at base speed D. slow down and overheat

Last Answer : Answer: A

Why Speed Control of Induction Motor is difficult compared to DC shunt motor?

Description : Why Speed Control of Induction Motor is difficult compared to DC shunt motor?

Last Answer : Answer: Speed Control of DC shunt motor can be possible by providing resistance in the armature and field circuits and varying the resistors speed changes can be carried out over a wide range. ... employed. Care should be taken that in the process efficiency and power factor should be maintained.

Give two basic speed control scheme of DC shunt motor?

Description : Give two basic speed control scheme of DC shunt motor?

Last Answer : Answer: 1. By using flux control method: in this method a rheostat is connected across the field wdg to control the field current. So by changing the current the flux produced by the field wdg can ... ) can be varied, and since speed is directly proportional to Eb-IaRa the speed can be controlled.

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.

A 4 pole lap wound dc shunt motor rotates at the speed of 1500 rpm, has a flux of 0.4 mWb and the total number of conductors are 1000. What is the value of emf? (A) 100 Volts. (B) 0.1 Volts. (C) 1 Volts. (D) 10 Volts.

Description : A 4 pole lap wound dc shunt motor rotates at the speed of 1500 rpm, has a flux of 0.4 mWb and the total number of conductors are 1000. What is the value of emf? (A) 100 Volts. (B) 0.1 Volts. (C) 1 Volts. (D) 10 Volts.

Last Answer : Ans: D Given N = 1500 rpm, Φ = 0.4 mWb, Z = 1000, P = 4, & A= 4 Therefore, Eb = NΦPZ / 60 A = 1500 x 0.4 x 4 x 1000 x 10^-3 / 60 x 4 = 60/6 = 10 volts

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

An unsaturated dc shunt motor runs at its rated speed when rated voltage is applied to it. If the

Description : An unsaturated dc shunt motor runs at its rated speed when rated voltage is applied to it. If the supply voltage to the motor is reduced by 25%, the speed of the motor  (a) Increases by 25% (b) Remains the same (c) Decreases by 25% (d) Decrease only slightly by an amount less than 25% 

Last Answer : An unsaturated dc shunt motor runs at its rated speed when rated voltage is applied to it. If the supply voltage to the motor is reduced by 25%, the speed of the motor Remains the same

Armature shunting method of speed control of dc shunt motor is preferred over annature resistance method...

Description : Armature shunting method of speed control of dc shunt motor is preferred over annature resistance method due to:  (1) Better speed regulation (2) Less loss in external resistance (3) Simplicity in control circuit (4) Reduced cost of controller

Last Answer : Armature shunting method of speed control of dc shunt motor is preferred over annature resistance method due to: Better speed regulation.

The most efficient method of increasing the speed of a 3.75KW d.c. shunt motor would be ...

Description : The most efficient method of increasing the speed of a 3.75KW d.c. shunt motor would be  A) Armature control B) Flux control C) Ward—Leonard D) Tapped—field control

Last Answer :  Flux control