Single Phase Motors
If a DC series motor is operated on AC supply, it will

All of the listed here
Have poor power factor
Spark excessively
Have poor efficiency

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Single Phase Motors
If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then

electrolytic capacitor will, in all probability, suffer break down
motor will not carry the load
motor will not come up to speed
current drawn by the motor will be excessively high

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