Question

Make four electromagnets with 20, 40, 60 and 80 turns. Connect them one by one to a battery of 2 cells. Bring the electromagnet near a box of pins. Count the number of pins attracted by it. Compare the strengths of the electromagnets.

Answer 1

Experiment Steps and Observations:

1. Materials Needed:

   • Coils with 20, 40, 60, and 80 turns.
   • Battery (2 cells).
   • Box of pins.

2. Procedure:

   • Wind the coils around an iron core to create electromagnets.
   • Connect each coil to the battery one by one.
   • Bring each electromagnet near the box of pins and count the pins attracted.

3. Observations:

   • 20 turns: Attracts a small number of pins.
   • 40 turns: Attracts more pins than the 20-turn coil.
   • 60 turns: Attracts even more pins.
   • 80 turns: Attracts the most pins.

Result:

Number of Turns	Pins Attracted
20	Few pins
40	More pins
60	Even more pins
80	Most pins

Conclusion:

The strength of the electromagnet increases with the number of turns in the coil. Therefore, the electromagnet with 80 turns is the strongest, followed by those with 60, 40, and 20 turns.

Visual Representation:

The provided image shows the electromagnets with different turns and the pins they attract, illustrating the increasing strength with more turns.