) …The formula for finding the diameter of a tungsten filament with a resistance of 0.041 is: d = √(4ρL/πr2R) where d is the diameter, ρ is the resistivity of tungsten, L is the length of the filament, r is the radius, and R is the resistance.
The resistivity of tungsten can be found in a materials properties database or by conducting an experiment to measure the resistance and length of a tungsten wire. It is typically around 5.6 x 10-8 Ωm for pure tungsten.
Yes, this formula can be used for filaments with different resistances as long as you have all the necessary variables (resistivity, length, and resistance) to plug into the formula.
Yes, there are other more accurate methods for calculating the diameter of a tungsten filament, such as using a micrometer or measuring the resistance at different lengths of the filament. However, the formula given is a good estimate for most cases.
Tungsten filaments are commonly used in incandescent light bulbs, vacuum tubes, and electron microscopes. They are also used in heating elements, thermocouples, and welding electrodes due to their high melting point and resistance to corrosion.