Q.

A particle is travelling 4 times as fast as an electron. Assuming the ratio of de-Broglie wavelength of a particle to that of electron is 2:1, the mass of the particle is

1 16 times the mass of e-  
2 8 times the mass of e-  
3 116 times the mass of e-  
4 18 times the mass of e-  

Ans.

(4)

Given: vparticle=4velectron and λparticle×2λelectron

Using λ=hp

λP=constant

∴ λparticle×pparticle=λelectron×pelectron

⇒λparticle×mparticle×vparticle

=λelectron×melectron×velectron

∴ mparticlevparticle=melectronvelectron2

⇒mparticle=melectron8