Saint-Gobain interview questions

These are few questions that I remember. 1.Explain the working principle of an electric motor? 2.What is efficiency of motors and generators? 3.What is difference between synchronous and asynchronous motor? 4.How synchronous motor maintains synchronous speed?What is slip? 5.What is formula of slip? 6.Find slip of a motor with speed 1300 rpm?What is drive? 7.How does it work?What is power factor? 8.Draw the digram of active power, reactive power.How can we improve power factor? 7.Draw a substation and explain? 8.Draw single line diagram of 11kV to 33kV transmission substation. 9.What happens when 11kV converted to 33kV?