MCQ
An electron of mass $m$ and charge $e$ is accelerated from rest through a potential difference $V$ in vacuum. The final speed of the electron will be
- A$V\sqrt {e/m} $
- B$\sqrt {eV/m} $
- ✓$\sqrt {2eV/m} $
- D$2eV/m$
✓
Answer
Correct option: C.
$\sqrt {2eV/m} $
c
(c) Kinetic energy $K = \frac{1}{2}m{v^2} = eV$ $==>$ $V = \sqrt {\frac{{2eV}}{m}} $
(c) Kinetic energy $K = \frac{1}{2}m{v^2} = eV$ $==>$ $V = \sqrt {\frac{{2eV}}{m}} $
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