Electronics Interview Question

-: “Electronics” Interview Question :-

1.What is a System?

Ans:A groupe of element that performe a similar or different Task .Basically follow spacific function.

2. What is Control System?

Ans:One kind of system where output and input are interrelated in between each other.The number of output is depand of given variabels of input.

1. What are different types of Control Systems?

Ans:There are two different type of control system 1.open loop and 2.closed loop.

4.What is a feedback in Control System?

Ans:The sampeled output are automatacily corrected .basicaly propertional signal of output is Feedback of a system.

5.Why Negative Feedback is preffered in the Control System?

Ans:The nagative feedback gives the batter visibility to user to understand the Error in output signal.

6.What is the effect of positive feedback on stability of the system?

Ans:posative feedbaack make more error.it is basically used in minor loop control structure.

1. What is Latching current?

Ans:In a system it thyristor starts conducting forward current for minimum value called Latching current.

1. What are the different losses that occur in thyristor while operating?

Ans:1.Forward conducting

2.loss duw to lakage.

3.power loss at gate.

4.swicthing loss.

9.What is meant by knee point voltage?

Ans:It is the time when CT           gets saturated.it is a very importent factor about chousing CT.

10.What is reverse power relay?

Ans:it is a flow ,Reverse Power flow relay are used in generating stations’s protection.

11.What will happen if DC supply is given on the primary of a transformer?

Ans:It will cause there only resistance will act in the electrical circuit.High electric current will flow.

12.What are the advantage of free wheeling diode in a Full Wave rectifier?

Ans:In an inductiveload it reduce the spark .       It reduce voltage spike .

13.Mention the methods for starting an induction motor?

Ans:1.Dol(Online starter)

2.start daier starter

3.rasistence starter

4.auto transformation

5 Reactor starter.

14.What is the power factor of an alternator at no load?

Ans:It will be zero lagging.

15.What is the function of anti-pumping in circuit breaker?

Ans:When breaker is close at one time by close push button,the anti pumping contactor prevent re close the breaker by close push button after if it already close.

16.What is stepper motor?

Ans:This is one kind of motor that is use to act input plus applied to it.

17.What is SF6 Circuit Breaker?

Ans:The full from of SF6 is  Sulpher hexa Flouride gas.

18.What is ferrantic effect?

Ans:when there is different in between volatege in output and input ,basically when the output voltage is higher then input.

19.What is meant by insulation voltage in cables? explain it?

Ans:It is a property of cable.it is the state when voltage is without rupturing.

20.Where should the lighting arrestor be placed in distribution lines?

Ans:At the time of trnformer distribution where feeders of 11kv and incomming feeder of 33kv and along it near power transformers in sub-stations.

21.Define IDMT relay?

Ans;Full form of it is inverse definite minimum time relay.In IDMT relay its operating is inversely proportional.

1. what is the full form of KVAR?

Ans:The full form of KVAR is `Kilo Volt Amps with Reactive component.

23.Why temperature rise is conducted in bus bars and isolators?

ans:it is necessary to test this devices use to checking if there is any temperature rise.

24.What if  four point starter

Ans:In this connection the shunt connection in four point stater is provided separately.

25.what is three point starter?

Ans:when the connection provide through a line.It is the main drawback of this technique.

26.Why the capacitors works on ac only?

Ans:In every case Generally capacitor gives infinite resistance.It give resistance to Dc connection.

27.How many types of colling system it transformers?

Ans:There are 5 type of colling They are:

1.oil natural,air natural

1. oil natural,air forced
2. oil forced,air forced
3. oil direct,water forced
4. oil forced,air forced

28.What is the principle of motor?

Ans:When current carrying conductor is placed in an magnetic field it make twesting move it is called principle of motor.

29.What is meant by armature reaction?

Ans:The effect of armature flu to main flux is called armature reaction. The armature flux may support main flux or opposes main flux.

30.What are the advantages of speed control using thyristor?

Ans:1. Higher Accurate

1. Fast Switching 3.low of cost.