Answer the following questions.
(a) Classify the following substances as magnetic or non-magnetic.
copper, phosphorus, iron, cobalt, soil, water, silver mercury, nickel, wood, oil.
(b) In olden times, how as a magnet placed in a compass?
Answer the following questions.
(a) Classify the following substances as magnetic or non-magnetic.
copper, phosphorus, iron, cobalt, soil, water, silver mercury, nickel, wood, oil.
(b) In olden times, how as a magnet placed in a compass?
(a)
Magnetic substances
Non-magnetic substances
Iron, cobalt, nickel
Phosphorus, soil, water, silver, mercury, wood, oil, copper
(b) A compass consists of a tiny pivoted magnet, usually in the form of a pointer or a needle that can turn freely in the horizontal plane. But in old times, the needles were magnetized by stroking them with a lodestone (a special form of the mineral magnetite) that aligned itself with the Earth's magnetic field. The needle did not keep its magnetism permanently, so a lodestone was carried on the ship so that the needle could be stroked whenever the magnetism wore off.
(a)
|
Magnetic substances |
Non-magnetic substances |
||
|
Iron, cobalt, nickel |
Phosphorus, soil, water, silver, mercury, wood, oil, copper |
(b) A compass consists of a tiny pivoted magnet, usually in the form of a pointer or a needle that can turn freely in the horizontal plane. But in old times, the needles were magnetized by stroking them with a lodestone (a special form of the mineral magnetite) that aligned itself with the Earth's magnetic field. The needle did not keep its magnetism permanently, so a lodestone was carried on the ship so that the needle could be stroked whenever the magnetism wore off.
