# Is it normal for a resistor to be hot?

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.

## Is it normal for a resistor to be hot? – Additional Questions

### Why do resistors sometimes get hot when in use?

The electric field within the resistor structure accelerates (does work on) the electrons increasing their kinetic energy however, this energy is quickly given up to the structure of the resistor via collisions; the resistor gets hotter.

### How can you tell if a resistor is bad?

A good resistor should test within its rated range. A bad resistor will either show infinite resistance or a measurement far higher than its rated resistance. In either case the resistor is no longer functioning properly.

### How do you tell if a resistor is burnt out?

Measure resistance from one end of the resistor to the damaged section. Again measure the resistance from the damaged section to the other end of the resistor. Add these two values of resistances. This is the approximate value of the burnt resistor.

### How fast does a resistor heat up?

The specific heat of silicon is 1.6 picoJoules per degree Centigrade per cubic micron. If your resistor body is 1cm cubed, that is 10,000 * 10,000 * 10,000 microns, or 1 Trillion cubic microns. In such a case, the resistor body will heat up by 1 degree C per second if one watt is dissipated.

### Why is my resistor smoking?

Resistors generate heat as current flows through them. If the applied voltage rises too high, they will heat up until they smoke or melt. 