What is a magnetic field? A magnetic field is a region or area in space where magnetic effects are felt - Leaving Cert Physics - Question 10 - 2006

1. Apparatus: Power source, closed circuit with a solenoid, and iron filings. 2. Procedure: Connect the solenoid to a power source to turn on the current. 3. Observation: Sprinkle iron filings around the solenoid and observe the pattern they form. The filings will align along the magnetic field lines that emerge from the solenoid. 4. Conclusion: The direction of the magnetic field can be determined using the right-hand grip rule, and the strength can be shown to vary with the number of turns and current. 5. Diagram: Include a labeled diagram showing the solenoid and the arrangement of iron filings.

One use of an electromagnet is in electric bells.

An advantage of an electromagnet is that the strength can be varied by changing the current.

An example of a device based on this effect is a relay or an electric bell.

If the current flows in the opposite direction, the direction of the force experienced by the aluminum foil will also reverse.

A larger current flowing through the aluminum foil will result in a greater upward force due to the increased interaction with the magnetic field.

If the aluminum foil is placed parallel to the magnetic field, there will be no upward force acting on it; it will experience no motion.

The force on the aluminum foil can be calculated using the formula: $F = I imes L imes B$ where:

• $F$ is the force,
• $I$ is the current (1.5 A),
• $L$ is the length of the foil (0.1 m), and
• $B$ is the magnetic flux density (3.0 T).

Thus, substituting the values: $F = 1.5 imes 0.1 imes 3.0 = 0.45 ext{ N}.$

So, the force acting on the aluminum foil is 0.45 N.