d c motors MCQs – Page 6

B. hoists

C. trains

D. cranes

A. Volume and grade of iron

C. Maximum value of flux density

D. Frequency of magnetic reversals

A. Voltage control method

C. Field control method

D. All above methods

A. D.C. shunt motor

B. Induction motor

D. D.C. series motor

A. series motor only

B. shunt motor only

C. compound motor only

A. it increases the input power con-sumption

C. both A. and B.

D. none of the above

B. Cumulatively compounded motor

C. Series motor

D. Shunt motor

A. rated voltage

C. rated r.p.m.

D. all of the above

A. none of the above is correct

B. a stronger commutating field is needed at low speed than at high speed

C. same commutating field is needed at low speed than at high speed

B. field control method

C. armature resistance control method

D. field divertor method

B. none of the above

C. series motors

D. compound motors

B. 4

C. 1

D. 2

B. back e.m.f. is equal to armature drop

C. flux is proportional to armature current

D. armature drop is negligible

A. differentially compounded

B. level compounded

D. under compounded

A. 2.36%

B. 6.77%

C. 8.84%

A. increase proportionately

B. remains unchanged

C. increase slightly

A. increased power consumption

C. damage to commutator segments

D. damage to commutator insulation

B. Universal motor

C. D.C. series motor

D. D.C. shunt motor

A. Fan motor

B. Drive for a water pump

C. Motor operation in A.C. or D.C

A. around 500 Q

C. 1000 Q

D. infinitely large