Hello Forum,(adsbygoogle = window.adsbygoogle || []).push({});

Most devices that are supposed to generate heat via resistance are connected to a constant voltage source. That means that the amount of power dissipated as heat is given by

P= V^2/R = I^2*R

This implies that the smaller the resistance the larger the current through the heating resistive element and the more heat is generated.

but conducting wires have very small resistance. However they don't dissipate much power because the current is not controlled by them but by the constant voltage source and the resistive heating element with its resistance R...

So, given a certain potential difference V, what is the ideal amount of resistance that a resistive heating element needs to have? If R is too small then too much current will flow: that may keep the dissipated power P small. If R is too large then the current I is too small (I^2) and the dissipated power is small again. There seem to be a suitable value of R to obtain the right and desired amount of heat generation...

In general, I would think R needs to be "small", whatever that may mean, to generate a sufficiently large current (I^2) and dissipate enough heat. So resistive heating elements (toasters, stoves, etc.) are small resistance devices...

thanks,

fog37

**Physics Forums - The Fusion of Science and Community**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# How much resistance for a heating resistive element?

Loading...

Similar Threads - much resistance heating | Date |
---|---|

How much ground counts as ground? | Feb 16, 2018 |

Can you damage your starter motor with too much current? | Jan 13, 2018 |

How much current does a cell phone use? | Oct 25, 2017 |

How much AC is there in a car battery | Sep 6, 2017 |

Resistance Wire Cut and Splice - Too Much Current Now | Apr 5, 2013 |

**Physics Forums - The Fusion of Science and Community**