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WorksheetsElectrical quiz
Total questions: 15
Worksheet time: 8mins
The main function of a commutator in a DC motor is to
increase speed
convert AC to DC
reverse current direction in armature
reduce sparking
Which part of DC generator actually cuts the magnetic flux
field winding
armature conductors
yoke
brushes
A DC generator works on the principle 0f
Fleming's left-hand rule
electromagnetic induction
lorentz force
ohm's law
Which AC motor is most commonly used in household appliances
synchronous motor
induction motor
stepped motor
DC motor
Which motor always run at constant speed
induction motor
DC shunt motor
synchronous motor
series motor
The armature core of a DC generator is made of laminated steel mainly to
reduce cost
increase strength
reduce eddy current losses
improve cooling
EMF is induced in which part of DC generator
field winding
armature conductors
yoke
brushes
Brushes in a DC generator are made of carbon because
it is cheap
it has high resistance
it reduces wear and sparking
it increases voltage
What would happen if brush contact is poor
voltage increases
no effect
excessive sparking and power loss
generator run faster
If the commutator is removed , the output of a DC generator will be
zero
DC with ripple
AC
high frequency DC
A DC generators work on the principle of
Faraday's law of electromagnetic induction
Flemming's left-hand rule
len'z law only
coulomb's law
EMF is induced in a DC generator when
magnetic field
armature conductors cut magnetic flux
load is connected
speed is zero
Why is the output of a DC generator DC even through EMF induced is AC
due to armature winding
due to brushes
due to commutator action
due to field winding
DC generator produces voltage because
conductors are stationary
magnetic field is stationary
conductors move in magnetic field
load is connected
Which statement is true about DC generator working principle
EMF is induced only when load is connected
generator actor depends on mechanical rotation
commutator produces EMF
brushes generate current
