Skip to main content
Electrical Engineering

Return to Answer

added 15 characters in body
Source Link
Matt Timmermans
Matt Timmermans
  • 1.4k
  • 7
  • 7

A heating element has neither "very high" nor "very low" resistance.

The total energy dissipated by the circuit is proportional to current, so the resistance of the heating element has to be low enough to draw sufficient current to generate enough heat.

However, of the total energy dissipated by the circuit, the portion of the energy dissipated by each part is proportional to its resistance, so the resistance of the heating element has to be high enough so that most of the energy is dissipated by the heating element itself instead of, for example, the wiring in the walls.

If you're connecting a heating element to the wall mains, there is a circuit breaker involved that limits the current so that your wiring doesn't get too hot. A heating element designed to deliver maximum heat (in a kettle, for instance) will draw as much current as it can while staying safely below that limit.

A heating element has neither "very high" nor "very low" resistance.

The total energy dissipated by the circuit is proportional to current, so the resistance of the heating element has to be low enough to draw sufficient current to generate enough heat.

However, of the total energy dissipated by the circuit, the energy dissipated by each part is proportional to its resistance, so the resistance of the heating element has to be high enough so that most of the energy is dissipated by the heating element itself instead of, for example, the wiring in the walls.

If you're connecting a heating element to the wall mains, there is a circuit breaker involved that limits the current so that your wiring doesn't get too hot. A heating element designed to deliver maximum heat (in a kettle, for instance) will draw as much current as it can while staying safely below that limit.

A heating element has neither "very high" nor "very low" resistance.

The total energy dissipated by the circuit is proportional to current, so the resistance of the heating element has to be low enough to draw sufficient current to generate enough heat.

However, of the total energy dissipated by the circuit, the portion of the energy dissipated by each part is proportional to its resistance, so the resistance of the heating element has to be high enough so that most of the energy is dissipated by the heating element itself instead of, for example, the wiring in the walls.

If you're connecting a heating element to the wall mains, there is a circuit breaker involved that limits the current so that your wiring doesn't get too hot. A heating element designed to deliver maximum heat (in a kettle, for instance) will draw as much current as it can while staying safely below that limit.

Source Link
Matt Timmermans
Matt Timmermans
  • 1.4k
  • 7
  • 7

A heating element has neither "very high" nor "very low" resistance.

The total energy dissipated by the circuit is proportional to current, so the resistance of the heating element has to be low enough to draw sufficient current to generate enough heat.

However, of the total energy dissipated by the circuit, the energy dissipated by each part is proportional to its resistance, so the resistance of the heating element has to be high enough so that most of the energy is dissipated by the heating element itself instead of, for example, the wiring in the walls.

If you're connecting a heating element to the wall mains, there is a circuit breaker involved that limits the current so that your wiring doesn't get too hot. A heating element designed to deliver maximum heat (in a kettle, for instance) will draw as much current as it can while staying safely below that limit.