Question

A large flat metal surface has a uniform charge density $(+,\sigma )$. An electron of mass m and charge $\rho$ leaves the surface at point A with speed u and returns to it at point B. Disregarding gravity the maximum value of AB is :

• A. $\frac{2{\mu }^{2}m{\epsilon }_0}{\sigma \rho }$
• B. $\frac{{\mu }^2\cdot \rho {\epsilon }_0}{\mu \rho }$
• C. $\frac{{\mu }^2\rho }{{\epsilon }_{0}m\sigma }$
• D. $\frac{{\mu }^2\sigma \rho }{\epsilon \cdot m}$

Answer 1

The correct option is A $\frac{2{\mu }^{2}m{\epsilon }_0}{\sigma \rho }$