Electric Machine Design PART 11 ONLINE Multiple Choice Questions

Electric Machine Design PART 11

Category –EE Online Test

Attempt Free Electric Machine Design PART 11 Here. Read The Important Electrical MCQ From Below.

151. When D is the diameter and L is the length of rotor of an induction motor, the best power factor can be obtained when (P = no. of poles)
(A) D=L
(B) D = PF
(C) D = √(PL)
(D) D = 1.35 P √L.

152. The power factor of the induction motor will be __________ if the magnetizing current is __________
(A) low……low
(B) high……..high
(C) high…..low
(D) low ……. high.

153. The magnetizing current of an induction motor will be __________ for __________ air gap
(A) larger ………. smaller
(B) larger ……… larger
(C) smaller……. larger
(D) smaller ……….. smaller.

Electric Machine Design PART 11

154. In induction motors, small air gap __________ power factor and __________ noise level
(A) increases ………. reduces
(B) reduces ………. increases
(C) reduces……….also reduces
(D) increases……….also increases.

155. In induction motors, larger air gap __________ noise level and __________ cooling
(A) increases ………. improves
(B) reduces ………. improves
(C) reduces……….jeopardises
(D) increases……….jeopardises.

156. In case of induction motors, phase reactance of the winding is __________ proportional to the number of slots per pole per phase
(A) directly
(B) inversely.

157. In the design of induction motors, normally the number of slots per pole per phase is taken as
(A) two
(B) three
(C) three or more
(D) three or less.

158. Normally open type stator slots in induction motors are not provided because
(A) exciting current increases
(B) coils cannot be slid through the top
(C) time required for the winding will be large
(D) none of the above.

Electric Machine Design PART 11

159. In induction motors provided with open type slots the exciting current is __________ and power factor is __________
(A) high……….high
(B) low……….low
(C) high……….low
(D) low ………. high.

160. Which type of slots are generally used in induction motors ?
(A) Open type
(B) Semi-closed type
(C) Closed type
(D) None of the above.

161. In induction motors, the difference between the number of stator and rotor slots should not be
(A) P
(B) 2 P
(C) 5P
(D) any of the above.

Electric Machine Design PART 11

162. For avoiding cogging in induction motor the difference between the number of stator and rotor slots should not be
(A) P
(B) 3P
(C) 5 P
(D) any of the above.

163. In induction motor which of the following depends on the leakage reactance ?
(A) starting torque
(B) maximum torque
(C) starting current
(D) all of the above.

Electric Machine Design PART 11

164. Leakage reactance in induction motors may result from
(A) slot leakage flux
(B) overhang leakage flux
(C) differential leakage flux
(D) all of the above.

165. The slip rings of wound rotor machines are made from
(A) electrolytic copper
(B) brass
(C) cast iron
(D) mild steel.