Make coils of turns 25, 50, 75, and 100. Connect them to the same cell one by one. Note the deflection in a magnetic compass placed in the same position in all the cases. Report your observations. Draw conclusion of the effect of number of turns of the coil on the strength of the electromagnet.
The observations show that as the number of turns of the coil increases, the deflection of the compass needle also increases.
A coil with 25 turns shows the least deflection, while a coil with 100 turns shows the maximum deflection.
This demonstrates that the strength of an electromagnet increases with an increase in the number of turns of the coil.
More turns of wire create a stronger magnetic field for the same amount of current, making the electromagnet more powerful.
Explanation
The chapter states in the 'Think like a scientist' section that the increase in number of turns of the coil makes the coil a stronger magnet. The strength of an electromagnet can be changed by changing the number of turns of the coil. This activity allows students to observe this relationship directly and conclude that more turns result in a stronger electromagnet.
Solution Steps
As the number of turns of the coil increases, the deflection of the compass needle also increases.
A coil with 25 turns shows the least deflection, while a coil with 100 turns shows the maximum deflection.
The strength of an electromagnet increases with an increase in the number of turns of the coil.
More turns of wire create a stronger magnetic field for the same amount of current, making the electromagnet more powerful.