To maximise the magnetic linkage and flux density between the primary and secondary windings.
yes core is usefull in transformer since it it increase the permeability for the flux (i..e,it offers less relucyance path thanj air ).Their by decresing the losses in the transformer.
The main application for a core type transformer is to increase voltage from a standard 240v supply up to 415v instead of using a 3 phase supply.
To reduce heat generated and eddy current losses in transformer's core during operation.
500w iron core transformer .that kind of size
It is the current transformer core meant for metering.
by using an iron core
A 'core type' transformer core is one in which the primary windings and secondary windings are placed around each of the limbs, as opposed to a 'shell type' core, in which the two windings are placed across the centre core. A core-type core is a magnetic circuit equivalent to an electric series circuit, whereas a shell-type core is equivalent to an electric parallel circuit. This is better answered with a diagram, so I suggest that you do a search on the internet.
AL means transformer core property
In general, the lower the frequency of operation, the more weight must be added to the core laminations to avoid magnetic field saturation. This increases the size and weight of the transformer as the frequency decreases.
The container the transformer core and windings are placed inside is the tank.
i think Transformer operates AC and ferrite core operates in DC
potential transformer is to maser and protection purpose the ivt is used for synchronicing purpose