railway DFCCIL Junior Executive 2023 (CBT 1 & CBT 2) Mock Test Electrical Machines Alternator and Synchronous Motors
Choose the INCORRECT statement with respect to synchronous machines.
1
The rotating air gap field and the rotor in the machine rotate at the same speed.
2
The power factor of the machine is always closer to 0.9 lag at any condition.
3
It runs at a constant speed at steady state when it is connected to fixed supply with variable load.
4
The rotor poles are excited by a DC current, and its stator windings are connected to an AC supply.