Two technicians are replacing an induction motor on a water pump into the fermentation vats in Elsinor brewery. The old American motor was rated at $240$ vac, $60$ Hz$,6$ HP$,1800$ rpm$.$ The new European motor is rated at $240$ vac, $50$ Hz$,6$ HP$,1800$ rpm$.$

Bob says that the new motor will rotate at a faster speed that the old motor, filling the vat faster, so the motor$-$on time in the PLC needs to be reduced.

Doug says that both motors are rated $1800$ rpm$,$ so the PLC program does not need changing.

Question $9$ options:

Only Doug is correct.

Both Bob and Doug are correct.

Neither Bob nor Doug are correct.

Only Bob is correct