Question:

An electron of mass m and a photon have the same energy E. The ratio of de-Broglie wavelength associated with them is:

(E2m)12

1c(E2m)12

c(2mE)12

1c(2mE)12(cbeing velocity of light)

For an electron, λ = h/√(2mE)
For photon, E = pc ⇒ λPhoton = hc/E
⇒ λ/λPhoton = h/√(2mE) × E/hc = (E/2m)^(1/2) / c = (E/2m)^1/2 / c