Category: D.C. Generators

A. Lenz’s law
B. Ohm’s law
C. Faraday’s law of electromagnetic induction
D. none of the above

A. rectifier
B. primemover
C. rotating amplifier
D. power pump

A. to reduce the reluctance of the mag¬netic path
B. to spread out the flux to achieve uniform flux density
C. to support the field coil
D. to discharge all the above functions

A. using conductor of annealed copper
B. using commutator with large number of segments
C. using carbon brushes of superior quality
D. using equiliser rings

A. only if the resistance of the field circuit is less than critical value
B. only if the resistance of the field circuit is greater than critical value
C. irrespective of the value of the resistance in the field circuit
D. none

A. separately excited generator
B. shunt generator
C. series generator
D. compound generator

A. to reduce eddy current losses
B. to enhance flux density
C. to amplify voltage
D. to provide mechanical balance for the rotor

A. 40 percent
B. 25 percent
C. 10 percent
D. 5 percent

A. neutralise the commutating self induced e.m.f.
B. neutralise the armature reaction flux
C. neutralise both the armature reaction flux as well as commutating e.m.f. induced in the coil
D. perform none of the above functions

A. The direction of that generator is reversed
B. The speed of that generator is increased
C. The field of that generator is weakened
D. That generator takes large share of loads