CoachEvery lamp, motor and appliance carries a nominal voltage — the push it is built for, stamped on its base or plate: a flashlight bulb “3.5 V”, a car headlamp “12 V”, a kettle “230 V”. Fed its nominal voltage, the device performs as designed; fed much less, it sulks — dim lamp, lazy motor; fed much more, it burns out — brilliantly, once.
Examples
Example 56.7 (Matching lamp to battery)
A “3.5 V” bulb on the flat battery: slightly overdriven — bright, and short-lived. On a single cell: a sleepy orange glow. On the battery: one dazzling instant, then the thin thread parts — the filament’s obituary. The label is a contract: honor it, and the lamp lives its advertised life.