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

970 RPM

940 RPM

960 RPM

920 RPM

970 RPM

940 RPM

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Electrical Machines
The total core loss of a 400 V, 50 Hz transformer is 2400W, when it is supplied by 200 V, 25 Hz loss is 800W. Calculate eddy current loss and hysteresis loss?

800W, 1600W

1600W, 800W

1000W , 1400W

1400W, 1000W

800W, 1600W

1600W, 800W

1000W , 1400W

1400W, 1000W

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Electrical Machines
A 3 - ÃŽÂ¦, 6 pole, 50 Hz IM has a rotor speed of 987 rpm find rotor frequency?

60 Hz.

0.70 Hz.

0.65 Hz.

0.75 Hz.

60 Hz.

0.70 Hz.

0.65 Hz.

0.75 Hz.

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Electrical Machines
In salient pole synchronous machine, if direct axis reactance and quadrature axis reactance is equal, then power developed due to reluctance is

infinite value

maximum

any of the above

zero

infinite value

maximum

any of the above

zero

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Electrical Machines
A transformer has resistance and reactance in per unit as 0.01 and 0.04 respectively. Its voltage regulation for 0.8 power factor lagging and leading will be

6% and -4%

3.2% and -1.6%

None of these

4.8% and -3.2%

6% and -4%

3.2% and -1.6%

None of these

4.8% and -3.2%

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Electrical Machines
A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be

1.8 9 Ω

1.79 Ω

2 .1 Ω

3.1 Ω

1.8 9 Ω

1.79 Ω

2 .1 Ω

3.1 Ω

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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 The total core loss of a 400 V, 50 Hz transformer is 2400W, when it is supplied by 200 V, 25 Hz loss is 800W. Calculate eddy current loss and hysteresis loss?

Electrical Machines A 3 - ÃŽÂ¦, 6 pole, 50 Hz IM has a rotor speed of 987 rpm find rotor frequency?

Electrical Machines In salient pole synchronous machine, if direct axis reactance and quadrature axis reactance is equal, then power developed due to reluctance is

Electrical Machines A transformer has resistance and reactance in per unit as 0.01 and 0.04 respectively. Its voltage regulation for 0.8 power factor lagging and leading will be

Electrical Machines A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be

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
The total core loss of a 400 V, 50 Hz transformer is 2400W, when it is supplied by 200 V, 25 Hz loss is 800W. Calculate eddy current loss and hysteresis loss?

Electrical Machines
A 3 - ÃŽÂ¦, 6 pole, 50 Hz IM has a rotor speed of 987 rpm find rotor frequency?

Electrical Machines
In salient pole synchronous machine, if direct axis reactance and quadrature axis reactance is equal, then power developed due to reluctance is

Electrical Machines
A transformer has resistance and reactance in per unit as 0.01 and 0.04 respectively. Its voltage regulation for 0.8 power factor lagging and leading will be

Electrical Machines
A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be