An electron of mass m with an initial velocity V=V0^i(V0>0) enters an electric field E=-E0^i(E0=constant>0) at t=0. If λ0 is its de-Broglie wavelength initially, then its de-Broglie wavelength at time t is?

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The diagram will be :-
Initial velocity=V0
Acceleration is constant :-
Final velocity=v=v0+eE0mt(at time t)
Now, at t=0 ⇒de-Broglie wavelength=λ0
⇒λ0=hmv0
Let at time t, de-Broglie wavelength=λ
Then, λ=hmV=hm(V0+eE0tm)=hmV0+eE0t=11/λ0+eE0t/h=λ.hh+eE0λ0t=λ01+eEoλ0th=λ=λ0(1+(eE0mV0)t)