Friday, 4 October 2013

Electrical Engineering Questions

1. What are the operation carried out in Thermal power station?
 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

2. What is the difference between Electronic regulator and ordinary rheostat regulator for fans?
 The difference between the electronic and ordinary regulator is the fact that in electronic reg. power losses tend to be less because as we minimize the speed the electronic reg. give the power necessary 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 achievespeed control.

3. What is 2 phase motor?
 A two phase motor is often a motor with the the starting winding and the running winding have a phase split. e. g; ac servo motor. where the auxiliary winding and the control winding have a phase split of 90 degree.

4. What does quality factor depend on in resonance?
Quality factor q depends on frequency and bandwidth.

5. What are the types of power in electrical power?
 There are normally three types of power are counted in electrical power. They are,
• Apparent power
• Active power
• Reactive power

6. 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.

7. What is slip in an induction motor?
Slip can be defined as the distinction between the flux speed (Ns) and the rotor speed (N). Speed of the rotor of an induction motor is always less than its synchronous speed. It is usually expressed as a percentage of synchronous speed (Ns) and represented by the symbol ‘S’.

8. Why link is provided in neutral of an ac circuit and fuse in phase of ac circuit?
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.

9. State the difference between generator and alternator?
Generator and alternator are two devices, which converts mechanical energy into electrical energy. Both have the same principle of electromagnetic induction, the only difference is that their construction. Generator persists stationary magnetic field and rotating conductor which rolls on the armature with slip rings and brushes riding against each other, hence it converts the induced emf into dc current for external load whereas an alternator has a stationary armature and rotating magnetic field for high voltages but for low voltage output rotating armature and stationary magnetic field is used.

10. What is ACSR cable and where we use it?
ACSR means Aluminium conductor steel reinforced, this conductor is used in transmission & distribution.


Pjseee93 on 21 November 2014 at 00:12 said...

Thanks for All

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