5F15.10 - Electrical Equivalent of Heat

Code Number:
Demo Title:
Electrical Equivalent of Heat
Relationship between Thermal and Electrical Energy
Area of Study:
Electricity & Magnetism
Countdown Timer, Insulated Flask, 250 Watt Heater, AC Current Projection Meter, Ring Stand, Digital Thermometer, 2 Digital Meters (Amperage and Voltage), Cord for Multimeter, and Beaker with Water.

Set up as shown and by running the experiment for a set amount of time, measuring the voltage and current, and the temperature rise, you should be able to calculate the electrical equivalent of heat.

Measure 1 liter of water into the Dewar.  Place the covering which contains the heater and bead thermocouple onto the Dewar.  Set the countdown timer for 5 minutes.  This heater runs at about 3.5 amps and will heat the 1 liter of water approximately 30 degrees Celsius in 5 minutes.

If using the larger knife style heater with the above conditions you can expect the heater to run at about 2.5 amps and give a temperature rise of over 20 degrees Celsius in 5 minutes.

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