Question

Find the initial momentum of electron if the momentum of electron is changed by Pm and the De Broglie wavelength associated with it changes by 0.50%.

Answer 1

As You Know , 

De Brogli Equation :

λ = h/mv 

λ = h/P....(1)

Let P0 be the initial Momentum and P is the decrease in momentum .

When  wavelength changed by 0.5%

λ + 0.5λ/100 = h/P0-P

100.5λ/100 = h/P0-P----(2)

By 1 and 2 

P0 = 1.99P 

Answer 2

Answer:

De Brogli Equation :

λ = h/mv λ = h/P....(1)

Let P0 be the initial Momentum and P is the decrease in momentum .

When  wavelength changed by 0.5%λ + 0.5λ/100 = h/P0-P100.5λ/100 = h/P0-P----(2)By 1 and 2 P0 = 1.99P

Explanation: