- #1

dwd40physics

- 32

- 0

- Homework Statement
- Explain why heating elements use resistance of low resistance rather than high resistance.

- Relevant Equations
- P = I^2 x R

Hi,

I understand mathematically why using low resistance results in a greater heating effect. Could someone give an intuitive and microscopic picture of why the current contributes more to a greater power dissipation by the resistor rather than the resistance contribution to the power dissipation.

I understand by proportionality (V=IR) that if you half the resistance across the load (resistor) the current doubles. Since P = I^2 x R the power dissipated is a factor of 2 greater (factor 4 for the current and factor 1/2 for the resistance).

The model I use is that electrons collide with lattice atoms and convert their KE to the lattice atoms and thus cause the heating element (resistor) to heat up. Can someone explain how this differs from using a high resistance where I assume that the heating effect due to lattice vibrations would be greater? What makes using a low resistance better than a high resistance.

Many thanks.

I understand mathematically why using low resistance results in a greater heating effect. Could someone give an intuitive and microscopic picture of why the current contributes more to a greater power dissipation by the resistor rather than the resistance contribution to the power dissipation.

I understand by proportionality (V=IR) that if you half the resistance across the load (resistor) the current doubles. Since P = I^2 x R the power dissipated is a factor of 2 greater (factor 4 for the current and factor 1/2 for the resistance).

The model I use is that electrons collide with lattice atoms and convert their KE to the lattice atoms and thus cause the heating element (resistor) to heat up. Can someone explain how this differs from using a high resistance where I assume that the heating effect due to lattice vibrations would be greater? What makes using a low resistance better than a high resistance.

Many thanks.