demonstrations:nichrome_wire_kettle
Nichrome Wire Kettle
Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★★☆ Can be done by science teachers
Safety: ★★☆ Some safety precautions required to perform safely
Categories: Electricity, Energy, Heat
Alternative titles: Heating Water with Nichrome Wire
Summary
A coil of nichrome wire is used to heat water in a beaker by converting electrical energy into heat energy through resistance, demonstrating the principle behind an electric kettle.
Procedure
- Wrap a length of nichrome wire around a pencil to form a tight coil, leaving about 5–6 cm of wire free at each end.
- Remove the coil from the pencil and place it into a beaker so the coil sits near the bottom.
- Use Blu-tack if necessary to secure the wire ends on the edge of the beaker.
- Fill the beaker with enough water to fully cover the nichrome coil.
- Attach one alligator clip to each end of the nichrome wire.
- Connect the clips to a power pack or a 9-volt battery.
- Place the setup on a heat-proof mat.
- Switch on the power and observe the water heating with a thermometer.
Links
How to make an electric kettle experiment - Caleb Salagaras:
Variations
- Use different voltages from the power pack to compare heating speed.
- Try using different lengths or thicknesses of nichrome wire to observe how resistance affects heating.
Safety Precautions
- The nichrome wire becomes extremely hot - do not touch it while the power is on.
- Always place the experiment on a heat-proof mat.
- Keep the power source and connections dry at all times.
- Disconnect the power before adjusting the wire or moving the setup.
- Supervision is required when using electrical equipment.
Questions to Consider
- What form of energy is converted into heat in this experiment? (Electrical energy.)
- Why does nichrome wire get hot when current passes through it? (Its high resistance converts electrical energy into heat energy.)
- What are the bubbles that form on the wire? (They are air or water vapor produced as the water heats up.)
- How does increasing voltage affect the heating rate? (Higher voltage increases current and therefore produces more heat.)
- How does this model demonstrate the operation of a real electric kettle? (Both use a resistive heating element to convert electrical energy into heat to boil water.)