197. If Ta be the torque and la the armature current for a D.C. motor, then which of the following relation is valid before saturation?
A. Ta oc la
B. Ta oc
C. Ta oc 1a2
D.TaOc
198. Which D.C. motor is generally preferred for cranes and hoists?
A. Series motor
B. Shunt motor
C. Cumulatively compounded motor
D. Differentially compounded motor
199. Three point starter can be used for
A. series motor only
B. shunt motor only
C. compound motor only
D. both shunt and compound motor
200. Sparking is discouraged in a D.C. motor because
A. it increases the input power consumption
B. commutator gets damaged
C. both (a) and (b)
D. none of the above
201. Speed control by Ward Leonard method give uniform speed variation
A. in one direction
B. in both direction below normal speed only
C. above normal speed only
D.
202. Flywheel is used with D.C. compound motor to reduce the peak demand by the motor, compound motor will have to be
A. level compounded
B. under compounded
C. cumulatively compounded
D. differentially compounded
203. Following motor is used where high starting torque and wide speed range control is required.
A. Single phase capacitor start
B. Induction motor
C. Synchronous motor
D. D.C. motor
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