Answer is 0.

Solution:

MRS=delta(x2)/delta(x1)

Good 1 is neutral it means that little change in delta(x2) makes infinity change in delta(x1). It means delta(x1)= infinity => MRS=0

It is net neutral but the oxygen carries a delta negative charge and the hydrogens delta positives so it is polar

The star connection has three phase terminal leads and one neutral lead. In case of delta connection it has got three phase terminal leads. the star connection is generally represented by Mercedes symbol with neutral line drawn from the mid point. The delta is represented like a triangle symbol with noneutral line shown.

A three phase delta system does not use a neutral in its operation.

In a three phase transformer, the primary winding is often configured in a Delta. The delta winding configuration does not use a neutral. The secondary winding is often in a Wye configuration, which does have a neutral.

The Delta configuration is typically used for transmitting power to various locations, and thee phase loads where a neutral is not needed. The Wye configuration is typically used to distribute power in a facility where there are single phase loads that need a neutral.

There are other reasons to use either Wye or Delta, such as grounding issues, but I think the short answer is probably what you're looking for (I hope).

Hope this helps!

Dave