Surprise Quiz 2 - Aircraft Systems

Stator consists of three sets of winding each at __________ degree to each other.

• 90

• 60

• 180

• 120

In a D.C. generator, the iron losses mainly take place in _______________________.

• Yoke

• Armature rotor

• Brushes

• Commutator

___________________ is used to determine the direction of current in D.C generator.

• Fleming's left hand rule

• Fleming's right hand rule

• Faraday's law

• Lenz law

Choose the condition to get maximum power in a DC motor.

• Ea = 2 x supply voltage

• Ea = supply voltage

• Supply voltage = 2 x Ea

• supply voltage = 4 x Ea

What will happen to torque if back emf and speed of the DC motor is doubled?

• Remain unchanged

• Reduce to one-fourth value

• Increase four folds

• Be doubled

Calculate phase voltage in a star connected three phase system with the line voltage of 200V.

• 67V

• 115V

• 120V

• 346V

A single-phase AC generator has twelve poles and it runs at 600 r.p.m. Find the output frequency of the generator.

• 50Hz

• 60Hz

• 120Hz

• 180Hz

A commutator reverses the current produced by the generator every _______________ degree.

• 60

• 90

• 120

• 180

Identify the phenomenon by which rotor operates at a lower speed than that of the rotating magnetic field.

• Rotation

• Slip

• Torque

• Induction

Choose the design frequency to get optimum efficiency in a brushless AC generator.

• 400Hz

• 100Hz

• 200Hz

• 50Hz