| illumination |
| impulse | |
| inductance | | |
| infrared rays | |
| interference | |
| internal combustion engine | |
| ionosphere | |
| ionization potential | |
|
|
| joule |
| joule's law in electricity | |
| joule's law in heat | | |
| joule thomson effect |
|
| kelvin | |
| kepler's laws | |
| kilogram | |
| kinetic theory of gases | |
|
|
| kirchhoff's laws in electricity |
| kirchhoff's laws of radiation |
