What is the basic working principle of Tri vector meter?

WHAT IS A BASIC DIFFERENCE BETWEEN THYRISTOR,TRIAC AND A DIAC.AND WHAT R THERE APPLICATIONS?

if we know Fault level say 25 KA , How to decide busbar size for Distribution network of 1000 Amp Breaker ? Sample Calculation or Farmula Available or not ?

give single line diagram of D.O.L and star -Delta starter ?

explain impact of tariff on energy management..? and what is ABT tariff

what is meant by frequency ?

what is the difference between concentrated winding and Distributed winding in motor?

what is your aim

what is the clear formula to calculate cable size for a load

what is the formula for calculation of sac?

how regenerative breaking is done in electrical traction

what is voltage

Why VCB and SF6 breakers to be used in HT used by cant ACB of higher rating to be used for 11kv and 33kv.

WHAT IS THE SIGNIFICANCE OF VECTOR GROUPS IN TRANSFORMER? WHAT WILL BE EFFECT WHEN PHASE DISPLACEMENT CHANGES IN TRANSFORMER?WHAT IS THE NEED TO BE PHASE SHIFT CHANGE BETWEEN THE PRIMARY AND SECONDARY WINDING

Can anyone explain me the operating principle of the megger tester?( I just know that its diflection relates with the ratio of currents of control & diflecting coil. I need more information as breif as possible)