An electron with kinetic energy K₁ enters between parallel plates of a capacitor at an angle ‘α’ with the plates. It leaves the plates at angle ‘β’ with kinetic energy K₂. Then the ratio of kinetic energies K₁ : K₂ will be

Correct Option - 4


Detailed Solution:

Since force will act in horizontal direction so vertical component of speed will be same

v₁ cos α = v₂ cos β

$\Rightarrow \frac{K_1}{K_2}={\left(\frac{v_1}{v_2}\right)}^2=\frac{co{s}^2\beta }{co{s}^2\alpha }$

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