Chapter Name: Electromagnetism
Activity Name: Current flow in Electromagnetism
This experiment explores the magnetic field created by a current-carrying wire. A wooden plank with a hole is placed on a table, and a retort stand is positioned on the plank. A 24-gauge copper wire is passed through the hole and arranged vertically without touching the stand.
The two ends of the wire are connected to a switch and a 3 (or 9) volt battery. Compass needles are placed in a circular path around the hole. When the circuit is closed, current flows through the wire, creating a magnetic field.
- Wooden plank with a hole
- Retort stand
- 24-gauge copper wire
- Rubber knob for retort stand
- Compass needles
- 3 (or 9) volt battery
Step by Step Procedure:
- Take the wooden plank and make a hole in it.
- Place the plank on the table.
- Position the retort stand on the plank.
- Pass the 24-gauge copper wire through the hole in the plank and the rubber knob of the retort stand, ensuring the wire is arranged vertically and does not touch the stand.
- Connect the two ends of the wire to the battery via the switch.
- Place 6 to 10 compass needles in a circular path around the hole, aligning their center with the hole.
- Use a 3 (or 9) volt battery in the circuit.
- Switch on the circuit to allow current to flow through the wire.
As current flows through the wire, the directions of the compass needles change, and they align tangentially to the circular path.
- Take appropriate safety measures while handling electrical components.
- Use low voltage batteries to avoid any hazards.
- Ensure that the wire is arranged vertically without touching the retort stand.
Lesson Learnt from Experiment:
The experiment demonstrates that the magnetic field lines around a straight current-carrying wire are circular and closed loops. The direction of the magnetic field lines can be determined using the right-hand thumb rule, where the thumb points in the direction of the current and the curled fingers show the direction of the magnetic field.