Question

A proton, a neutron, an electron and an α-particle have same energy. λ_p, λ_n, λ_e and λ_α are the de Broglie's wavelengths of proton, neutron, electron and α particle respectively, then choose the correct relation from the following :

Options

• λ_p = λ_n > λ_e > λ_α 

• λ_α < λ_n < λ_p < λ_e 

• λ_e < λ_p = λ_n > λ_α 

• λ_e = λ_p = λ_n = λ_α 

Answer 1

λ_a < λ_n < λ_p < λ_e 

Explanation:

As λ = `"h"/"p"="h"/sqrt(2"m"("K"."E"))` 

As K.E = constant

So, λ ∝ `1/sqrt"m"` 

As, m_e < m_p < m_n < m_α. So, λ_e > λ_p > λ_n > λ_α