a) Electric brushes b) Armature c) Commutator d) Magnetic poles Ans: (c)
a) Torque b) Magnetic field c) Speed d) Current Ans: (a)
a) D.C b) A.C. single phase c) A.C. two phase d) A.C. three phase Ans: (a)
a) Motor action b) Generator action c) Both (a) and (b) d) All of these Ans: (c)
a) Only motor action takes place b) Motor action precedes generator action c) Generator action precedes motor action d) Both take place precedes simultaneously Ans: (b)
a) D.C. machines b) A.C. machines c) Electro-mechanical convertors d) Heat converters Ans: (c)
a) Armature is rotating and field is fixed b) Field is rotating and armature is fixed c) Either (a) or (b) d) None of these Ans: (a)
a) A hetro-polar structure b) A horse shoe structure c) (a) above (b) d) None of these Ans: (a)
a) 2 b) 4 c) 6 d) Number of poles in the machine or 2 Ans: (d)
a) Overcome the back emf b) Supply armature ohmic drop c) Supply fied ohmic drop d) Both (a) and (b) Ans: (d)