A pair of parallel metal plates are kept with a separation ' \(\mathrm{d}\) '. One plate is at a potential \(+\mathrm{V}\) and the other is at ground potential. A narrow beam of electrons enters the space between the plates with a velocity \(v_{0}\) and in a direction parallel to the plates. What will be the angle of the beam with the plates after it travels an axial distance L?
(A) \(\tan ^{-1}\left(\frac{\mathrm{eVL}}{\mathrm{mdv}_{0}}\right)\)
(B) \(\tan ^{-1}\left(\frac{\mathrm{eVL}}{\mathrm{mdv}_{0}^{2}}\right)\)
(C) \(\sin ^{-1}\left(\frac{\mathrm{eVL}}{\mathrm{mdv}_{0}}\right)\)
(D) \(\cos ^{-1}\left(\frac{e V L}{m d v_{0}^{2}}\right)\)
Ans(B)
