To observe how the strength of an electromagnet depends upon the number of turns of the wire.
Magnets are substances that have the ability to draw in metallic materials like iron. The magnets can be temporary (such as electromagnets) or permanent magnets. The naturally occurring magnets are permanent magnets. A current carrying wire behaves like a magnet. When a compass is brought closer to the wire, the magnetic influence can be seen as a deflection of the needle. This magnetic effect of electric current can be used for making temporary magnets referred to as electromagnets. To maintain a magnetic field, an electromagnet needs a constant flow of electricity. Consequently, electricity may be utilised to switch the electromagnets on and off. An electromagnet usually consists of a long coil of insulated copper wire wound around an iron rod. When both ends of the coil are connected to a cell, a current flows through the coil. This generates a magnetic effect, magnetising the iron rod making it an electromagnet. The iron rod in this case is said to be the core of electromagnet. An electromagnet attracts magnetic objects (such as pins, clips, and other objects made of iron, steel, etc.) similar to real magnets when they are brought close to it.
The strength of electromagnets depends on several factors such as: Strength of current passing through the coil: As the current flowing through the coil increases, strength of electromagnet increases. We can increase the current by adding more cells in the circuit.
In fact, electromagnets are the strongest magnets made.
An electromagnet's magnetism can be activated or deactivated as required. With a permanent magnet, this is impossible. We can increase the strength of an electromagnet by either increasing the number of turns in the coil or the current that flows through it.