Demonstration Manual

Electricity and Magnetism

DEM27 - Electromagnet Demonstration

Objective:

- To demonstrate the characteristics of electromagnets.

Apparatus:

• Solenoid, air core
• Steel core
• Copper core
• Brass core
• Aluminum core
• Power supply, 54-c
• Stand, clamp
• Tap Switch

Method:

The air coil (solenoid) is clamped and mounted at an angle of about 45 . The "LD-DC" power supply is connected to the coil and current is adjusted to about 2.5 A.D.C. The various core materials are inserted. The iron core will be restrained from falling out by magnetic forces. All cores can be tested for magnetic properties by touching nails etc. to them. When power is switched off, even the iron core slips out, by gravity.

Note:

Do not use too high a D.C. current for "too long," as the plastic core will soften by heat and will not be straight.