φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%.

Electrical Machines
φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%.

960 RPM

920 RPM

940 RPM

970 RPM

960 RPM

920 RPM

940 RPM

970 RPM

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Electrical Machines
Find the number of poles required, when the frequency is 50Hz and speed of the motor is 500 rpm?

10

5

24

12

10

5

24

12

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Electrical Machines
In a DC series generator, the terminal voltage with increase in load will

remain nearly constant

increase gradually and then stay at rated voltage

increase to rated voltage and then may decrease

decrease

remain nearly constant

increase gradually and then stay at rated voltage

increase to rated voltage and then may decrease

decrease

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Electrical Machines
In a star - delta starting of an IM

resistance is inserted in the rotor.

reduced voltage is applied to the stator.

applied voltage per stator phase is 57.7 % of a line volt

line voltage is 57.7 % of stator voltage.

resistance is inserted in the rotor.

reduced voltage is applied to the stator.

applied voltage per stator phase is 57.7 % of a line volt

line voltage is 57.7 % of stator voltage.

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Electrical Machines
Induction motors normally use cast aluminium rotor because aluminium is

lighter in weight.

easy to cast owing to its low melting point and is easily available.

of low resistivity.

cheaper in cost.

lighter in weight.

easy to cast owing to its low melting point and is easily available.

of low resistivity.

cheaper in cost.

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Electrical Machines
In dc machine armature windings are placed on rotor because of the necessity for

development of torque.

electromechanical energy conversion.

generation of voltage.

commutation.

development of torque.

electromechanical energy conversion.

generation of voltage.

commutation.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines

Electrical Machines φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%.

Electrical Machines Find the number of poles required, when the frequency is 50Hz and speed of the motor is 500 rpm?

Electrical Machines In a DC series generator, the terminal voltage with increase in load will

Electrical Machines In a star - delta starting of an IM

Electrical Machines Induction motors normally use cast aluminium rotor because aluminium is

Electrical Machines In dc machine armature windings are placed on rotor because of the necessity for

Electrical Machines
φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%.

Electrical Machines
Find the number of poles required, when the frequency is 50Hz and speed of the motor is 500 rpm?

Electrical Machines
In a DC series generator, the terminal voltage with increase in load will

Electrical Machines
In a star - delta starting of an IM

Electrical Machines
Induction motors normally use cast aluminium rotor because aluminium is

Electrical Machines
In dc machine armature windings are placed on rotor because of the necessity for