Design of Electrical Machines Practice Test 9

1. Why is the three phase reluctance motor preferred over single phase reluctance motor?

single phase reluctance motors have the phenomenon of over voltage

single phase reluctance motors have low output

single phase reluctance motors have high losses

single phase reluctance motors have the phenomenon of hunting

2. What is the range of the frequency constant?

0.5-1.0

0.86-1.0

0.82-1.0

0.9-1.0

3. What is the symbol used for the total mmf required for the teeth?

Tmt

ATt

4. How is the reluctance motor with respect to a synchronous motor and are the field windings?

small synchronous motor with field windings

small synchronous motor without field windings

large synchronous motor without field windings

large synchronous motor with field windings

5. What is the symbol used for the number of turns in the secondary winding?

Tsw

Tws

6. What is the formula for the slot pitch factor in design of rotors?

slot pitch factor = 1/3.14*rotor diameter*number of rotor slots

slot pitch factor = 3.14*rotor diameter/number of rotor slots

slot pitch factor = 3.14/rotor diameter*number of rotor slots

slot pitch factor = 3.14*rotor diameter*number of rotor slots

7. What is the formula of the pole arc of the universal commutator motor?

pole arc = ratio of armature axial length to armature diameter + pole pitch

pole arc = ratio of armature axial length to armature diameter * pole pitch

pole arc = ratio of armature axial length to armature diameter - pole pitch

pole arc = ratio of armature axial length to armature diameter / pole pitch

8. The high values actually apply for the small motors below 150 W.

false

true

9. What is the hybrid method of computer aided design?

advanced analysis method

different method

combination of advanced and synthesis method

advanced synthesis method

10. What is the symbol used for the pitch of commutator segments in the dc motor?

Ret

Pcs

BETAc