An electron is projected is in figure at a speed of 6 × 10⁶ ms^–1 at an angle of 45⁰; E = 2000 Vm^–1 directed upward, d = 3cm and l =10cm. Will the electron strike either of the plates?

$\begin{array}{l}\text{ Range }=\frac{{\mathrm{u}}^2\sin 2\mathrm{\theta }}{\mathrm{a}}=\frac{{\mathrm{u}}^2}{\mathrm{a}}\\ =\frac{36\times {10}^{12}\times 9.1\times {10}^{-31}}{1.6\times {10}^{-19}\times 2000}=10.1\mathrm{cm}\end{array}$

Max height reached:

$\mathrm{H}=\frac{{\mathrm{u}}^2{\sin }^2\theta }{2\mathrm{a}}=\frac{{\left(6\times {10}^6\right)}^2\times {\left(\frac{1}{\sqrt{2}}\right)}^2}{2\times \frac{3.2\times {10}^{15}}{9.1}}=0.025 \mathrm{m}=2.5 \mathrm{cm}$

Since max height reached by electron is less than the separation between the plates, it will not strike the upper plate.

Hence, it will touch the lower plate at the edge.