Recently Updated Interview Questions in Electrical and Electronic Engineering                            
 
                                                                   
                                   
                                       
                                            
                                                                                                 What are the advantages of VSCF wind electrical system?
                                             
                                         
                                        
                                                    
											                                            
                                            Advantages of VSCF wind electrical system are :
* No complex pitch changing mechanism is needed.
* Aero turbine always keeps going at maximum efficiency point.
* Extra energy in the high wind speed region of the speed – duration curve can be extracted
* Significant reduction in aerodynamic stresses, which are associated with constant – speed operation.                                        
                                                    
                                            
                                        
                                     
                                
                                                                   
                                   
                                       
                                            
                                                                                                 Why electricity in India is in the multiples of 11 like 11kv, 22kv, 33kv?
                                             
                                         
                                        
                                                    
											                                            
                                            Transformer Induced voltage equation contains 4.44 factor.
E=4.44*f*T*phi
E -Induced emf per phase
T -number of turns
f -frequency
phi -maximum flux per pole
From the equation we see that E is proportional to 4.4 and it is in turn multiple of 11.
So always transmission voltage is multiple of 11