Doubting Dennis doesn't believe in electromagnetism so he makes an electromagnet to prove his teacher wrong. To his surprise, the electromagnet works and he's able to pick up metal objects with it. Even still, he's not satisfied with his electromagnet because it's very weak.

Answer 1

To make a stronger electromagnet, Doubting Dennis could follow these steps:

1. Increase the number of wire coils: The strength of an electromagnet is directly related to the number of coils of wire wrapped around the iron core. By increasing the number of wire turns, Dennis can increase the strength of the magnetic field.

2. Use a thicker wire: A thicker wire will allow more current to flow through the coil, increasing the strength of the magnetic field. However, thicker wire can be harder to wrap tightly, so Dennis may need to balance the wire thickness with the number of coils he can fit around the core.

3. Increase the current: The strength of an electromagnet also depends on the amount of current flowing through the wire. Dennis can try using a power supply with a higher voltage, or connect the electromagnet to a stronger battery to increase the current flowing through the coil.

4. Use a soft iron core: Soft iron is a material that is easily magnetized and demagnetized, making it an ideal core material for electromagnets. Dennis should make sure he is using a high-quality, soft iron core in his electromagnet for maximum effect.

5. Improve the insulation between wire layers: Dennis should ensure that there is proper insulation between the wire layers and between the wire and the iron core to prevent short circuits which could weaken the electromagnet.

6. Increase the length of the iron core: The iron core should protrude out of the end of the coil slightly to ensure the best possible magnetic field strength. Dennis can consider using a longer core if he is not getting the desired results with his current setup.

After following these steps, Doubting Dennis should be able to make a stronger electromagnet that is capable of picking up heavier metal objects with ease. This should help him gain a better understanding of electromagnetism and prove to him that his teacher was indeed correct.