Is it normal for a resistor to be hot? When a resistor has been overloaded with voltage exceeding its power rating, the resistor will become very hot to touch, darken considerably and possibly even melt or catch on fire. Although a resistor may appear damaged at this point, it can still be functioning.
How do you keep a resistor from overheating?
Why does a resistor get hot GCSE? Some energy may be dissipated as thermal energy. This means that if a current flows through a resistor, the resistor will heat up. Electrons collide with ions in the lattice of the resistor. As the electrons bump into the ions, energy is transferred causing the ions to vibrate and heat up.
What happens when a resistor heats up? When electricity is conducted through a resistor, heat is generated and dissipated through the surrounding air. Under excessive voltage, a resistor generates so much heat that it cannot dissipate the heat quickly enough to prevent burning.