PTC/Resistance for 150°C at 220V AC and 24V DC

[sumit_volant]

What should be value of PTC/ Resistance to raise its temperature to 150 deg Celsius for 220V AC and 24V DC..
Please explain this with required formula...

 

[f95toli]

Impossible to answer. It depends on how quickly it losses heat.
Remember that a resistor wil heat up only if it can't dump the dissipated energy quickly enough.

 

[berkeman]

What should be value of PTC/ Resistance to raise its temperature to 150 deg Celsius for 220V AC and 24V DC..
Please explain this with required formula...

What is the context of the question? Is it for a project or for schoolwork?