In different books, but also websites, there are different expressions for the Heisenberg's uncertainty principle. For example,
- $\Delta x \Delta p \ge h$ (from The Physics of Atoms and Quanta)
- $\Delta x \Delta p \ge \hbar/2$ or
- $\Delta x \Delta p \ge \hbar$ (Demtroder)
Which one of these notations is the correct one? Or, if they're all correct, could someone provide me with some examples or context where each of them is used?