Question

An electron is accelerated from rest through a potential difference 12 V. What is the change in electric potential energy of the electron? Explain your answer.

Answer 1

Explanations & Calculations

• If the potentials of the two points between which the charge moves in are taken to be $\small V_1\,\&\,V_2$ , then the associated potential energies would be $\small eV_1\,\&\,eV_2$.
• Then the change in potential energies is just the difference between these two.
• Therefore, it is as follows

$\qquad\qquad \begin{aligned} \small \Delta E_p&=\small e(V_2-V_1)\\ &=\small e\times12\,V\\ &=\small 1.6\times10^{-19}\times C\times 12\,JC^{-1}\\ &=\small 1.9\times10^{-18}\,J \end{aligned}$

• You need to know the charge of an electron to continue.