- #1
peteza
- 3
- 0
Homework Statement
The problem is that I cannot figure out why a filament will burn out in a particular spot. Higher resistance = lower current why does the filament heat up more?
Homework Equations
R2= R1[1+a(T2-T1)]
Resistance = (resistivity * L)/ A
R= V/I
The Attempt at a Solution
I know that tungsten oxide evaporates form the filament when a critical temperature is reached. This causes the cross sectional area of the filament to decrease and increases resistance. Increased resistance results in increased temperature. The filament gives off more heat as the cross sectional area decreases. This could be because the current is reduced so this excess energy has to go somewhere so it is converted to heat energy and radiated from the filament. I just don't understand how a resistor dissipates heat and why the light bulb 'choses' to burn out in a certain spot.