Misc Flashcards
Three 5-microfarad capacitors are connected in parallel. What is their total capacitance?
15 microfarad.
When capacitors are joined in parallel, the total capacitance is?
equal to the sum of the individual capacitors.
If the distance between the two plates of a capacitor is reduced, what will be the effect?
Capacitance increases.
The circuit shown is at resonance. If the value of the inductance is trebled, the impedance will?
reduce by one-third.
The strength of the EMF generated by a DC generator is given by which formula?
E = BlV.
The rotating part of a motor/generator is called?
armature.
No EMF is induced in the loop of a generator when?
it is moving parallel to the field.
The instantaneous value of the EMF induced in a rotating wire loop is?
directly proportional to the cosine of the angle between the loop and the field.
One purpose of the commutator is to?
switch the direction of the current flow every half cycle.
The power output of a DC generator is governed primarily by?
its ability to dissipate heat.
A DC machine has internal resistance due to?
armature windings, brushes and brushes to commutator contact.
Compensation windings are fitted to a generator in?
series with armature windings.
Armature reaction has the effect of?
reducing the output by distorting the magnetic field.
Reactive sparking may be overcome by?
decreasing the time constant of the armature by increasing its resistance.
