ELECTRICAL ENGINEERING QUESTIONS AND ANSWERS

Here are some Electrical Engineering questions which i came across in internet.I will give the answers for the questions.Hope it would be useful for all Electrical Engineers.Visitors please give your feedback so that i can improve in helping other Electrical Engineers.

ONLINE ELECTRICAL ENGINEERING TEST 1

    These questions were asked in the competitive exams.The test is for 10 minutes and you can submit the test if you have finished it early.Hope it would useful for all Electrical Engineers.More Tests would be conducted online related to the electrical subjects.Keep watching Online Electrical Engineering for more ....

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1. Advantage of transmitting power at high voltage is

   A) magnitude of current will be small

   B) power loss will be less

   C) it will reduce the voltage drop in the line impedance

   D) all the above

ANSWER :

D) all the above

2. An oscillator uses

   A) Positive feedback

   B) Negative feedback

   C) Both positive and negative feedback

   D) No feedback

ANSWER :

A) Positive feedback

3. The lightning arrestor is connected

   A) in series with the line

   B) between line and earth

   C) to a pole near the line

   D) to circuit breaker

ANSWER :

B) between line and earth

4. The earth's potential is taken as

   A) infinite

   B) supply voltage

   C) 1 volt

   D) zero

ANSWER :

D) zero

5. The value of diversity factor is

   A) less than one

   B) greater than one

   C) equal to one

   D) none of the above

ANSWER :

B) greater than one

6. Permeance is analogous to

   A) Conductance

   B) Reluctance

   C) Inductance

   D) Resistance

ANSWER :

A) Conductance

7. Electronic switching are becoming more and more popular because of

   A) noiseless operation

   B) long life

   C) smaller size and weight

   D) all the above

ANSWER :

D) all the above

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TRANFORMER OIL IMPORTANCE AND USES

Here i am answering another question asked by Amit.
What is the importance of Transformer Oil ?
Transformer Oil is a highly refined mineral oil that has excellent insulating properties and is very stable at high temperatures.It also serves as a coolant.

In a Transformer, the primary winding and secondary windings are placed inside a casing.To provide electrical insulation between the live parts inside the transformer casing we use Transformer Oil.Tranformer Oil should also withstand high temperatures for a long period.The cooling of transformer can be increased by providing cooling tubes and external fans outside the transformer casing.  

Buchholz Relay is a protective device used in transfomers.Also various testing is also done on the transformer to test the oil quality.Another important thing is we must have seen some tranformers bursting near our place.This occurs due to insulation failure inside the transfromer.Reason behind this might be the Transformer Oil used would have become old and lot of sludge would have formed which causes insulation failure.