Physics
It is easier to separate iron filings from sand than to separate iron filings from a metallic mixture. Why?
Answer
It is easier to separate iron filings from sand because sand is a non-magnetic substance and is not attracted to a magnet, whereas iron filings are magnetic and get attracted easily. However, in a metallic mixture, more than one metal may be magnetic. As a result, the magnet attracts other magnetic metals along with iron, making the separation of only iron filings difficult.
Related Questions
Roshan's parents gifted him magnets on his birthday. His parents told him that magnets could attract objects. He played with those magnets all day and experimented by attracting different materials onto it. He noticed that some materials got attracted to it while some didn't. After a few days, his magnets were not working well.
Now, answer the following questions.
(a) What materials do you think got attracted to the magnets?
(b) What materials do you think didn't get attracted to the magnets?
(c) Why do you think his magnets stopped working?
(d) What should Roshan do to fix his magnets?
Why do you think dropping a magnet demagnetises it?
Why doesn't the soft iron retain magnetism once the electric current stops flowing through the wire around it?
The strength of the magnetic field is defined as the measure of the intensity of a magnetic field in a given area of that field. The strength of the magnetic field is measured in a unit called Gauss. The following graph depicts the strength of a magnet at different temperatures.
Observe the graph carefully.
Now, answer the following questions.
(a) At what temperature is the strength of the magnet the highest?
(b) At what temperature is the strength of the magnet the lowest?
(c) Why is the strength of the magnet reducing with increase in temperature?
(d) Is there any way to strengthen the magnet again? Why/Why not?