Are carbon film resistors and metal film resistors equally safe to burn?
I want to explain to children that they need to carefully calculate and check resistor values. I don't only want to explain it, but also let them feel and see it.
In one step, I use three resistors in parallel, operating at their defined 0.25 W. They will get hot and the children can feel it. However, this may not show the danger enough, so I also want to let one of them catch fire.
A lot of things are obvious when performing this experiment
- keep the children in a safe distance
- use a fire-proof surface
- do the experiment outside, so there's good ventilation
- have a fire extinguisher near, just in case
- in any of our experiments, we use low voltage DC power source, < 24 V
However, there's one open question to me: we have 0.25 W carbon film resistors and 0.25 W and 0.6 W metal film resistors available. Are they equally safe to use?
My assumption would be that the carbon film resistors just burns to ash, but the metal film resistors might melt into liquid metal. Is it maybe even educational to do both experiments, because the result is so different?