全部书籍

专业

应用 关于 Coach 登录 开始阅读

书籍暂未推出简体中文版——当前显示英文版。

Physics · 术语表

什么是 Nominal voltage?

Definition 56.6 Primary & Middle School Physics · 第 56 章 — Voltage and the Voltmeter

Every 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.

示例

Example 56.7 (Matching lamp to battery)

A “3.5 V” bulb on the 4.5 V4.5\,\mathrm{V} flat battery: slightly overdriven — bright, and short-lived. On a single 1.5 V1.5\,\mathrm{V} cell: a sleepy orange glow. On the 9 V9\,\mathrm{V} 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.

在原文中阅读 →