Question

Why do we prefer to use soft iron core for making an electromagnet?

Answer 1

We use soft iron ore as electromagnet because we wish to make electromagnets temporary magnets i.e, they shld get magnetised as soon as the current flows through it and shld demagnetize when the current  flow stops......And also soft iron ore has a low retentivity.
If a alloy lyk steel is used it will become a permanent magnet