1.What is electric traction
Answer:Traction means using the electric power for traction system i.e. for railways,trams, trolleys etc. electric traction means use of the electricity for all these . now a days, magnetic traction is also used for bullet trains. basically dc motors are used for electric traction systems.

2.How can you start-up the 40w tube lite with 230v AC/DC without using any choke/Coil?
Answer:It's possible by means of Electronic choke.otherwise it's not possible to ionize the particles in tube. light, with normal voltage

3.What is "pu" in electrical engineering?
Answeru stands for per unit and this will be used in power system single line diagram there it is like a huge electrical circuit with no of componenes (generators, transformers, loads) with different ratings (in MVA and KV). To bring all the ratings into common platform we use pu concept in which, in general largest MVA and KV ratings of the component is considered as base values, then all other component ratings will get back into this basis.Those values are called as pu values. (p.u=actual value/base value).

4.Operation carried out in Thermal power station?Answer:The water is obtained in the boiler and the coal is burnt so that steam is obtained this steam is allowed to hit the turbine , the turbine which is coupled with the generator generates the electricity

5.Why link is provided in neutral of an ac circuit and fuse in phase of ac circuit?
Answer:Link is provided at a Neutral common point in the circuit from which various connection are taken for the individual control circuit and so it is given in a link form to withstand high Amps. But in the case of Fuse in the Phase of AC circuit it is designed such that the fuse rating is calculated for the particular circuit (i.e load) only.So if any malfunction happen the fuse connected in the particular control circuit alone will blow off.



6.what is the diff. btwn. electronic regulator and ordinary rheostat regulator for fans?Answer:The difference between the electronic and ordinary regulator is that in electronic reg. power losses are less because as we decrease the speed the electronic reg. give the power needed for that particular speed but in case of ordinary rheostat type reg. the power wastage is same for every speed and no power is saved.In electronic regulator triac is employed for speed control.by varying the firing angle speed is controlled but in rheostatic control resistance is decreased by steps to achieve speed control.

7.How tube light circuit is connected and how it works?Answer:A choke is connected in one end of the tube light and a starter is in series with the circuit. When supply is provided ,the starter will interrupt the supply cycle of AC. Due to the sudden change of supply the chock will generate around 1000volts . This volt will capable of to break the electrons inside the tube to make electron flow. once the current passes through the tube the starter circuit will be out of part. now there is no change of supply causes choke voltage normalized and act as minimize the current.