Question

The kinetic energy of a proton and that of an alpha- particle are 4eV and 1eV, respectively. The ratio of the de-Brogile wavelengths associated with them will be

(a) 2:1
(b) 1:1
(c) 1:2
(d) 4:1

​

Answer 1

Answer:

$\large\boxed{\sf{(c)\;\;1:2}}$

Explanation:

We know that ,

According to de Broglie hypothesis:

$\large{ \red{{ \lambda}^{2} \: \alpha \: \: \frac{1} {ke} }}$

where

$\lambda$ = wavelength

ke = kinetic energy

Now, the ratio of kinetic energy of proton to that of alpha particle is 4:1

Therefore,

The ratio of square of wavelength will be 1:4

Hence, ratio of wavelength will be (c) 1:2

Answer 2

Answer:

option B (1:1)

Explanation:

what many of do wrong in this question is

we forget to equate

four time of mass of proton is equal to the mass of alpha particle

Answer correctly solved by Kanishk modi

Student of Neerja modi school jaipur