Electrical Interview Questions: Electrical Machines (Set 1)

1.Electrical Question: What is Electrical Dynamo?

 Answer: An Electrical Dynamo is a machine that converts either mechanical energy in to electrical energy or electrical energy into mechanical energy. When a dynamo is made to driven by an mechanical force (prime mover) by a diesel engine, steam turbine, or water turbine so that it produces electrical output. During this process Dynamo acts as Electrical Generator. When dynamo draws electrical energy from the supply mains and drives mechanical devices such as rotating loads. During this process dynamo acts as Electrical Motor. 

In Simple words motor and generator action is a reversible process i.e, a same machine can be operated as electrical motor or electrical generator depends on the input power (mechanical power and electrical power) supplied to it.

2.Electrical Question: What is Faraday's Law of Electro magnetic Induction?

Answer: Faraday's Law Of Electro Magnetic Field induction helps in explaining the  production of electro magnetic field (EMF) in the Electrical Machines. Electro Magnetic Field (EMF) is induced when a space variation or time variation takes place between conductors or magnetic field.

In order to generate electro magnetic field (EMF) the requirements are: 

• Magnetic Field  
• Set Of Conductors 
•  Relative Space variation or the time variation

3.Electrical Question: What are different types of EMFs Induced in Electrical Machines?

Answer: Different types of Induced EMFs  produced in electrical machines are:

• Dynamic Induced EMF
• Static Induced EMF

Dynamic Induced EMF: This is the EMF induced in set of conductors which are being moved inside a steady or time variant magnetic field. The nature of EMF induced in a dc generator is dynamically or motional induced EMF.

Static Induced EMF: This is the EMF induced in set of stationary conductors which are placed in time varying magnetic field. The nature of EMF induced in a transformer is statistical induced emf.