Question

The strength of the magnetic field between the poles of an electromagnet would be unchanged if :

(a) current in the electromagnet winding were doubled
(b) direction of current in electromagnet winding were reversed
(c) distance between the poles of electromagnet were doubled
(d) material of the core of electromagnet were changed

Answer 1

The magnetic field strength between the poles of an electromagnet would remain the same if the direction of the current in the winding were reversed.

Step-by-step explanation:

The strength of the magnetic field between the poles of an electromagnet would be unchanged if the direction of current in electromagnet winding were reversed. Changing the direction of current would reverse the polarity of the electromagnet's poles but would not affect the strength of the magnetic field. Doubling the current would increase the strength of the field, doubling the distance between the poles would weaken the field at a given point because the field intensity decreases with distance, and changing the material of the core could either increase or decrease the field strength depending on the material's magnetic permeability.