Preference of strings on an EV are primarily a function of what type of pickup you have at the bridge. The magnetic pickups like you would find on a guitar will require a steel core string so the magnetic field is created. A piezo pickup, like shown here is typical of most "affordable" violins.

A high end violin like a Woods or NS Designs might have a mag pickup but they are almost as much or more than the whole EV you would buy as a beginner. A Barbarrea pickup can run $300 (just for the pickup!) so you don't find many on the entry level violins.

With that said, normally it is recommended to use a steel core string on the electrics because the steel is less dampening and most people play EVs' with effects boxes and amps so the string only has to vibrate, not move wood to create sound. In many respects if you have a very cheap or inexpensive pickup on your EV, you can just about use any type of string on it that suits your tastes.