Question

When an iron plate is put across the N and S poles of a horseshoe magnet ______?
A. It short circuits the effect of magnetism
B. It increases the effect of magnetism
C. Magnet regains its full strength once the plate is removed
D. Both (1) and (3)

Answer 1

A horseshoe magnet is a U shaped magnet with both ends [poles] close together for easy flow of magnetic flux or field lines. As a magnet with both polarities that is north and south poles, which are represented by N and S

Complete step by step answer: When an iron plate which is a conductor is placed between the poles or across the poles of a horseshoe magnet, the electric field is always intense or very high normally and observed to be high because of the closeness of the poles of the horseshoe magnet.
It then becomes short circuited after the iron plate is placed and therefore carries the charges that are supposed to flow from the North to South Pole of the horseshoe magnet.
So because of the iron plate between the poles of the horseshoe magnet which serves as a trapping specimen, the horseshoe magnet becomes fully strengthened and regains its full strength once the plate is removed. At this point there is no more breaching.
The correct option is Option D. When an iron plate is put across the North and South poles of a horseshoe magnet, it short circuits the effect of magnetism and magnet regains its full strength once the plate is removed.

Note: The poles of the magnet are close and as such the intensity or strength of magnetism is high and can only be reduced when a metal like an iron plate is introduced. A practical example also happens with other metals that exhibit ferromagnetism (metals that have the same or close to the properties of iron).