How faster is an induction cooker really? | Magnetic heating and COOLING

Brainiac75
30 Apr 202011:51
EducationalLearning
32 Likes 10 Comments

TLDRThis video explores the magnetocaloric effect, demonstrating how magnetism can heat and cool materials. It compares the efficiency of induction and resistive cookers, showing the superior heating of the former due to its magnetic field. The experiment then focuses on gadolinium, a highly paramagnetic metal, revealing a subtle temperature change when exposed to and removed from a magnetic field. The video concludes with a simple refrigeration cycle using magnetism, hinting at potential future applications in magnetic refrigerators.

Takeaways
  • 🧲 Magnetism can be used to change temperature, as demonstrated by the efficiency of induction cookers compared to traditional resistive heating elements.
  • 🔍 The magnetocaloric effect allows for heating and cooling through the use of permanent magnets, although the effect is subtle and requires precise measurement.
  • ⚠️ Safety precautions are important when handling strong magnets and working with hot substances like boiling water.
  • 📈 The induction cooker heats water faster due to its ability to induce eddy currents and magnetic hysteresis loss in the cookware, bypassing the need to heat the cookware itself first.
  • 🌡 The test showed that the induction cooker brought water to a boil significantly faster than the resistive cooker, highlighting the efficiency of AC magnetic fields for heating.
  • 🔌 Voltage plays a crucial role in the performance of resistive cookers, with higher voltage supplies leading to faster heating times.
  • 🌡️ Gadolinium, a highly paramagnetic metal, exhibits a noticeable magnetocaloric effect near room temperature, which was tested using a sensitive Pt-100 thermometer.
  • 📊 The Pt-100 thermometer provides high precision and resolution, measuring temperature changes as small as 0.01°C, and is minimally affected by magnetic fields.
  • 🔁 The magnetocaloric effect involves a thermodynamic process where the alignment of magnetic moments in a material transfers energy to the crystal lattice, causing a temperature change.
  • 🛠️ A refrigeration cycle based on the magnetocaloric effect could potentially be used in magnetic refrigerators, as demonstrated by the small temperature drop in the experiment.
  • 🎓 The video encourages learning more about science and problem-solving with resources like Brilliant, offering a discount for the first viewers using a provided link.
Q & A
  • What is the main topic of the video?

    -The main topic of the video is demonstrating how magnetism can be used to change temperature, specifically through the magnetocaloric effect and the efficiency comparison between induction and resistive cookers.

  • What is an induction cooker and how does it work?

    -An induction cooker is a kitchen appliance that uses an electromagnet to generate an AC magnetic field, which induces eddy currents in the cookware, heating it directly and subsequently the food or water inside.

  • What is the magnetocaloric effect mentioned in the video?

    -The magnetocaloric effect is a phenomenon where certain materials change temperature in response to changes in an applied magnetic field. The video specifically discusses the use of a permanent magnet to heat and cool gadolinium through this effect.

  • Why is the electromagnet in an induction cooker more efficient than a resistive heating element?

    -The electromagnet in an induction cooker is more efficient because it heats the cookware directly through induced eddy currents and magnetic hysteresis loss, skipping the need to first heat the cooker itself and then the cookware.

  • What is the difference in power usage between the induction cooker and the resistive cooker in the video?

    -The induction cooker uses around 800W more at 202V, while the resistive cooker uses only 630W at 212V. However, the induction cooker used less total electricity in the test.

  • Why does the video mention the importance of voltage for resistive cookers?

    -The video mentions the importance of voltage for resistive cookers because, according to Ohm's law and Joule heating formulas, a higher voltage supply results in more power available for heating with a fixed resistance.

  • What is gadolinium and how does it relate to the magnetocaloric effect?

    -Gadolinium is a highly paramagnetic metal that turns ferromagnetic just below room temperature. It exhibits a significant magnetocaloric effect, causing a small but detectable temperature change when subjected to a strong magnetic field.

  • How does the video demonstrate the magnetocaloric effect on gadolinium?

    -The video demonstrates the magnetocaloric effect on gadolinium by showing a temperature rise when gadolinium is placed in a strong magnetic field and a temperature drop when it is removed from the field.

  • What is the Pt-100 sensor used for in the video?

    -The Pt-100 sensor is used for measuring temperature with high precision and resolution. It is a platinum wire that has a resistance of 100 ohms at 0°C and exhibits a linear response between temperature and resistance.

  • How does the video suggest using the magnetocaloric effect for refrigeration?

    -The video suggests a refrigeration cycle where a magnetocaloric material is heated in a magnetic field, cooled down using a heat sink while still in the field, then the heat sink and field are removed allowing the material to cool down further, which can then cool a refrigerant passing through it.

  • What is the potential future application of the magnetocaloric effect discussed in the video?

    -The potential future application discussed in the video is the development of magnetic refrigerators, which could be commercially available in the future, providing an alternative to traditional refrigeration methods.

Outlines
00:00
🔥 Magnetism in Cooking: Induction vs. Resistive Heating

This paragraph introduces the video's theme of using magnetism to alter temperature, specifically in cooking. It compares the efficiency of induction cookers, which use an electromagnet to heat cookware directly through induced eddy currents, to traditional resistive heating elements. The video presents a test to determine which method boils water faster, with the induction cooker showing superior performance due to its ability to heat the cookware immediately without preheating itself. The summary also touches on the importance of voltage in the efficiency of resistive cookers and the overall energy consumption of both methods.

05:03
🧲 Exploring the Magnetocaloric Effect with Gadolinium

The second paragraph delves into the concept of the magnetocaloric effect, which allows certain materials like gadolinium to heat up or cool down in the presence or absence of a magnetic field. The video demonstrates this effect using strong magnets and a highly sensitive thermometer with a Pt-100 sensor. The narrator explains the thermodynamic process behind the magnetocaloric effect, involving the alignment of magnetic moments and the transfer of energy to the crystal lattice, resulting in a temperature change. The summary also describes an experiment to utilize this effect for refrigeration, using the magnet as a heat sink and showing a slight temperature drop in the gadolinium after several cycles.

10:04
🎓 Learning Science with Brilliant and Supporting the Channel

The final paragraph shifts focus to learning and community support. It promotes Brilliant, an educational platform offering interactive courses on scientific problem-solving, with a special mention of a course on chemical reactions. The narrator encourages viewers to sign up through a provided link for a free trial and mentions a discount for the first 200 users. The paragraph also acknowledges the support of patrons who have contributed to the production of the video and invites others to contribute to keep the channel running, with a link provided in the video description.

Mindmap
Keywords
💡Magnetism
Magnetism is the force of attraction or repulsion that arises between objects due to their magnetic properties. In the video, magnetism is central to the theme as it is used to demonstrate how temperature can be altered, particularly through the use of an induction cooker and the magnetocaloric effect. The script mentions the electromagnet in an induction cooker, which uses magnetic fields to heat cookware and water efficiently.
💡Induction Cooker
An induction cooker is a type of stove that uses electromagnetic fields to heat cookware directly, skipping the need for the stove itself to get hot. The video script compares the efficiency of an induction cooker to a traditional resistive heating element cooker, highlighting the rapid heating of water in the induction cooker due to the magnetic field-induced electrical resistance in the cookware.
💡Magnetocaloric Effect
The magnetocaloric effect refers to the change in temperature of a material in response to a changing magnetic field. The video script describes this phenomenon as a subtle effect that can be used to heat and cool materials, specifically mentioning gadolinium, which exhibits a strong magnetocaloric effect near room temperature.
💡Gadolinium
Gadolinium is a rare earth element that is highly paramagnetic at room temperature and becomes ferromagnetic just below room temperature. In the video, it is used to demonstrate the magnetocaloric effect, showing a slight temperature change when exposed to a magnetic field and then removed from it.
💡Paramagnetic
Paramagnetic materials are those that are weakly attracted to an external magnetic field and become magnetized in the presence of that field. Gadolinium is highlighted in the script as the most paramagnetic element at room temperature, which is why it exhibits a noticeable magnetocaloric effect.
💡Thermometer
A thermometer is a device used to measure temperature. The script describes the use of a Pt-100 sensor thermometer, which measures temperature based on the resistance of a platinum wire, to detect the small temperature changes caused by the magnetocaloric effect.
💡Heat Capacity
Heat capacity is the amount of heat energy required to raise the temperature of a substance by a certain amount. The script explains that when gadolinium is in a magnetic field, its heat capacity decreases because the magnetic moments align, leading to an increase in temperature without a gain in energy.
💡Refrigeration Cycle
A refrigeration cycle is the process by which a substance is cooled and then used to cool another substance, typically in a refrigeration or air conditioning system. The video script outlines a potential magnetocaloric refrigeration cycle, using the temperature change of a magnetocaloric material in response to a magnetic field to cool a refrigerant.
💡Ohm's Law
Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance between them (I = V/R). The script mentions Ohm's Law in the context of explaining why a resistive cooker is less effective at lower voltages, as it directly affects the power output for heating.
💡Joule Heating
Joule heating, also known as resistive heating, is the process by which the passage of an electric current through a conductor releases heat. The script refers to Joule heating when discussing the heating mechanism of a resistive cooker, where the cookware heats up due to the electrical resistance.
💡Magnetic Field
A magnetic field is a region around a magnetic material or a moving electric charge within which the force of magnetism acts. The script discusses the effects of a magnetic field on both the induction cooker and the magnetocaloric effect, showing how the alignment of magnetic moments within a material can lead to temperature changes.
Highlights

Magnetism can be utilized to change temperature effectively, as demonstrated by the efficiency of induction cookers.

Permanent magnets can induce heating and cooling through the magnetocaloric effect, which is subtle but measurable.

Strong magnets require careful handling to avoid injury.

Boiling water and hot substances like gadolinium should be handled with caution.

An induction cooker's efficiency is compared to a resistive heating element cooker in a simple test.

Induction cookers heat the cookware directly, bypassing the need to heat the appliance itself first.

The induction cooker achieves a rolling boil faster than the resistive cooker.

Voltage is a critical factor for the performance of resistive cookers, with higher voltage leading to faster heating.

Gadolinium, a highly paramagnetic metal, is used to demonstrate the magnetocaloric effect.

The Pt-100 sensor in the thermometer provides high precision and resolution for temperature measurements.

The magnetocaloric effect causes a small but detectable temperature change in gadolinium when exposed to a magnetic field.

The experiment refines the testing method to accurately capture the magnetocaloric effect on camera.

The temperature of gadolinium increases when in a magnetic field due to the alignment of magnetic moments.

The alignment of magnetic moments transfers energy to the crystal lattice, increasing the temperature.

Removing gadolinium from a magnetic field results in a temperature drop as the magnetic moments regain their fluctuation.

The magnetocaloric effect can be harnessed for refrigeration, with a cycle involving heating and cooling in a magnetic field.

Experiments show that the refrigeration cycle using magnetism is effective, although the temperature drop is minimal.

The potential for magnetic refrigerators to become commercially available in the future is discussed.

Brilliant.org is recommended for those interested in learning more about scientific problem-solving.

A special offer for Brilliant's 'The Chemical Reaction' course is provided to the audience.

Transcripts
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