We know $$E = q V$$ where $E$ is the energy (in Joules), $V$ is the potential difference (in Volts), and $q$ is the charge. Why is this equation true and how we prove it?
Answer
There are various ways to decide which of the assumptions are primary and which of them are their consequences but $E=VQ$ may be most naturally interpreted as the definition of the potential.
The potential energy is a form of energy and the potential (and therefore voltage, when differences are taken) is defined as the potential energy (or potential energy difference) per unit charge, $V = E/Q$. That's equivalent to your equation. The potential energy is proportional to the charge essentially because of the linearity of Maxwell's equations (the superposition principle). Once we know about the proportionality, we must just give a name to the proportionality factor between $E$ and $Q$ and we simply call it potential (or voltage).
No comments:
Post a Comment