KVPY2017PhysicsElectrostatics
A particle of charge q and mass m enters a region of a transverse electric field of E ₀ j with initial velocity v₀ i . The time taken for the change in the de Broglie wavelength of the charge from the initial value of ₀ to ₀ / 3 is proportional to
Options
- Aq m
- Bm q
- Cq m
- Dm q
Correct answer
B. m q
Step-by-step solution
= h mv 1 v v = v _ y ²+ v ₀² v _ y = u _ y + a _ y t v _ y =0+ qE ₀ ~m t (3 v ₀ )= v _ y ²+ v ₀² v _ y ²=8 v ₀² q E ₀ ~m t =2 2 v ₀ t = 2 2 ~m q E ₀ v ₀ t m q