The device that uses a resistor to transform electrical energy into light and heat is an incandescent light bulb.

Here's how it works:

* Filament: The incandescent bulb contains a thin wire filament made of a material with high resistance, typically tungsten.

* Electrical Current: When electricity flows through the filament, its high resistance causes it to heat up significantly.

* Light and Heat: The intense heat generated by the filament causes it to glow, emitting light and heat.

While incandescent bulbs are still used in some applications, they are becoming less common due to their energy inefficiency.