Iron and steel cylinders can be both magnetized by placing them inside a solenoid connected to a dc supply. Which pair of statements about the magnetic strengths of the iron and steel cylinders is correct? Supply on Supply on, then offA. iron stronger Iron strongerB. iron stronger. Steel stronger C. Steel stronger. Iron stronger D. Steel stronger. Steel stronger Which answer is correct? And why? Thanks (:
The answer should be C. When the supply is left on for a substantial amount of time, steel, being a hard magnetic material (harder to magnetise / demagnetise) would retain its magnetism more effectively than iron, which is a soft magnetic material (easier to magnetise / demagnetise). When the supply is switched on and off within a short time, then iron would be magnetised more quickly and effectively (i.e. stronger) than steel, which require a longer time to become substantially magnetised.
Which makes it pair B, as iron is better with current on, but loses more when off. Steel is not as good with current on, but retains more when off.
