AC Quiz

Which one of the following methods is used to find voltage regulation?

• Direct loading method

• EMF method

• Ampere turns method

• All of the above

The small diameter and large axial length are the features of ___________________ rotor?

• Salient pole rotors

• Smooth cylindrical rotors

• Both a and b

• None of the above

What are the advantages of an armature as a stator?

• Easy cooling

• More efficient

• Easy insulation

• All of the above

The hysteresis and eddy current is the cause of _____________ loss?

• Copper loss

• Windage loss

• Core loss

• Stray loss

Which one of the following methods is also known as the Potier triangle method?

• MMF method

• ZPF method

• Synchronous impedance method

• None of the above

If the armature reaction of an alternator produces a magnetization effect on the main field then the power factor should be

• Unity

• Zero leading

• Zero Lagging

• Only Leading

Which among the following are the applications of synchronous motors?

• compressors

• fans

• blowers

• all of the above

As the speed of an alternator increases

• the frequency increases

• the frequency remains constant but power factor decreases

• the frequency decreases

• None of the above

When the PF of an alternator is unity then the armature flux will be

• Demagnetisation

• Zero

• Cross Magnetisation

• none of the above

For 50Hz and 2 poles, the max speed of alternator is

• 2500rpm

• 2000rpm

• 1500rpm

• 3000rpm