## IB Physics Glossary

Browse the glossary using this index

Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q |

**R**| S | T | U | V | W | X | Y | Z | ALL

## R |
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## Radioactive decay lawis written as an exponential decay function N: #nuclei at time tN: initial number of nuclei_{0}t: time Note or A: activity at time tA _{0}: initial activity of samplet: time | |

## Random error is a fluctuating error often present in experiments. It is linked to precision: imprecise data => "high" random error; precise data => "low" random error. Repeated measurements do reduce random errors. Sources of random errors can include varying reading/human error and other randomly flucuating factors which cannot be controlled during experiments. | |

## Rayleigh Criterion for images of two wave sources to be just resolved the maximum of one diffraction pattern is coincident with the first minimum of the other. (d)
The minimum anglular separation in the diffraction pattern, If two objects at a distance r from the pupil/telescope, separated by distance s, are just resolved then, since which can be used to solve typical problems on resolution. | |

## Resisitvity can be found from the resisitivity equation where R is the resitance, << Simulation >> | |

## Resistance | |

## Resistance combinations occur when resistances or components are placed in series and/or in parallel combinations. The main differences between the two types of combinations are
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## Resonance occurs when an object is forced to vibrate at its natural frequency with a very large increase in amplitude. (d) Resonance is the opposite to damping. If external driving frequency, f, equals to the natural frequency, f, then _{0}f = f or _{0}f/f, and resonance occurs._{0} = 1Notice the resonance amplitude decreases with damping, and the natural frequency decreases. | |

## rms voltage or current | |