What Affects the Strength of an Electromagnet?

What Affects the Strength of an Electromagnet?

Aim What is the effect of increasing the current and increasing the number of coils when picking up paper clips?

Definition First of all, an electromagnet has to be defined. An electromagnet can also be called a Solenoid, Which consists of a core of iron and then wire is wrapped round it.

Prediction

I predict that as the current carried in the wire gets stronger, so will the magnetic field surrounding the electromagnet. Therefore, I think that the amount of paper clips picked up will increase as the voltage gets higher until the electromagnet can't pick up any more paper clips. I also predict that the more coils wrapped round the wire creates a bigger magnetic field allowing more paper clips to be picked up.

Variables

Thickness Coils

Length of wire

Core Material

If the paper clips are already slightly magnetized from previous experiments

Weight of the Paperclips

Number of Paperclips available

Equipment Mat - (To protect the surface of the bench)

Power Pack - (To control the voltage of the current)

*Battery Pack - (To control the voltage of the current)

Crocodile Clips - (To take the electricity to the Electromagnet)

Paper Clips - (To test the conductivity of the Electromagnet)

Electromagnet Iron Nail - (to act as a core) Wire - (wrapped around the core)

Test the Voltage Method 1. Take the Iron rod and wind the wire around it, leaving the two ends of the wire free.

2. Plug two crocodile clip leads into the Power pack and attach each crocodile clip to a different end of the wire which is wound around the rod.

3. Turn on the power to the required voltage (I had a problem with the power pack because they kept short circuiting so I decided to use a battery pack but they would drain very quickly and could only test 2, 4, and 6 volts) and then bring the box of paper clips up so that they are touching the Iron rod

4. If there are any paper clips still hanging, take them off and count them and record the results

The above method was repeated at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 & 12 Volts.

Testing the Number of Wires Method 1. Take the Iron rod and wind the wire around it 10 times increasing the number of coils by 10 each time up to 100 coils, leaving the two ends of the wire free.

2. Plug two crocodile clip leads into the Power pack and attach each crocodile clip to a different end of the wire which is wound around the rod.

3. Turn on the power to the required voltage* (I had a problem with the power pack because they kept short circuiting so I decided to use a battery pack but they would drain very quickly) and then bring the box of paper clips up so that they are touching the Iron rod

4. If there are any paper clips still hanging, take them off and count them and record the results

This experiment was a fair test because:

* The same box of paper clips was used each time.

* Only one factor (i.e. the current/the no. of coils) was changed.

* The core of the electromagnet always had the same surface area.

* The same equipment was used each time.

* The paper clips were all made of the same material

The experiment may not have been a completely fair test, as I observed that the iron rod would attract about 1-2 paper clips when the electricity was turned