In a differentially compounded D.C. motor, if shunt field suddenly opens

A The motor will first stop and then run in opposite direction as series motor
B The motor will work as series motor and run at slow speed in the same direction
C The motor will work as series motor and run at high speed in the same direction
D The motor will not work and come to stop

Correct Answer: The motor will first stop and then run in opposite direction as series motor

Bissoy MCQ
#Electrical Engineering #D.C. Motors

Related Questions

If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens
A This will make armature to take heavy current, possibly burning it
B This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses
C Nothing will happen to motor
D Motor will come to stop
If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens
A Nothing will happen to the motor
B This will make armature to take heavy current, possibly burning it
C This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses
D Motor will run at very slow speed
The length of a rectangular field F is 3 km greater than the side of a square field M , and the width of field F is 3 km less then the side of field M. If the area of field M is m2 square km, what is the area of field F?
A m2 +6
B 6
C m2 - 6
D m2 +9
If the field of a D.C. shunt motor gets opened while motor is running
A The speed of motor will be reduced %
B The armature current will reduce
C The motor will attain dangerously high speed 1
D The motor will continue to run at constant speed
A cumulatively compounded long shunt generator when operating as a motor would be
A Cumulatively compounded long shunt
B Differentially compounded long shunt
C Cumulatively compounded short shunt
D Differentially compounded short shunt
Differentially compound D.C. motors can find applications requiring
A High starting torque
B Low starting torque
C Variable speed
D Frequent on-off cycles
A farmer has two rectangular fields. The larger field has twice the length and four times the width of the smaller field. If the smaller field has area K, then the area of the largest field is greater than the area of the smaller field by what amount?
A 4K
B 6K
C 7K
D 8K
A farmer has two rectangular fields. The larger field has twice the length and four times the width of the smaller field. If the smaller field has area K, then the area of the larger field is greater than the area of the smaller field by what amount ?
A 2K
B 5 K
C 6K
D 7K
If the speed of a D.C. shunt motor is increased, the back e.m.f. of the motor will
A Increase
B Decrease
C Remain same
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If the field circuit of an unloaded salientpole synchronous motor gets suddenly open-circuited, then
A it runs at a slower speed
B the motor stops
C it continues to run at the same speed
D it runs at a very high speed

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