Electrical Machines
In induction motor the 7th harmonic torque may make the motor rotate at (1 / 7)th synchronous speed. This is called

  harmonics.
  resonance.
  crawling.
  cogging.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
A bipolar dc machine with interpoles has a main-pole flux of ф per pole and an interpole flux of Фᵢ per pole. The yoke of the machine is devide into four quadrants by the main-pole axis and The commutation axis. The flux-distribution in the quadrants will be

 ½ ( ф + фᵢ ) in all the four quadrants
 ½ ( ф - фᵢ ) in all the four quadrants
 ½ ( ф + фᵢ ) in two diametrically opposite quadrants and ½ ( ф - фᵢ ) in the remaining two Quadrants
 ½ ( ф + фᵢ ) in two adjacent quadrants and ½ ( ф - фᵢ ) in the remaining two quadrants

ANSWER DOWNLOAD EXAMIANS APP