Question { Siemens, 25523 }

In a 3 phase squirrel cage induction motor why does rotor
rotate?
will 3 phase transformer rotate like a motor if it is
placed on bearings and powered up? give reason

Answer

motor consist of magnetic field if electric supply given to
motor flux produced in to it due to its magnetic field &
due to maggnetic field produced in it emf iduced in its &
rotation of rotor start .

Question { 15091 }

Why Aluminium wires are used for High tension(HT) lines?
11 KVA/32KVA & aboue

Answer

Due to low weight of aluminium as compare to copper and
easy to install. Sag is also minimum between the two polls.

Question { Jindal, 26538 }

Why HT cable have only 3 core ?

Answer

as per system contain only three phase thats why requirment
is for three core & in system used three core.