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If the deBroglie wavelength of an electr...

If the deBroglie wavelength of an electron is equal to `10^(-3)` times the wavelength of a photon of frequency `6xx10^(-14)Hz` then the speed (in m/s) of electron is equal to:
(Speed of light `=3xx10^(8)m//s)`
Planck's constant `=6.63xx10^(-34)J.s`
Mass of electron `=9.1xx10^(-31)kg)`

A

`1.7 xx 10^(6)`m/s

B

`1.45 xx 10^(6)`m/s

C

`1.8 xx 10^(6)` m/s

D

`1.1 xx 10^(6)`m/s

Text Solution

Verified by Experts

The correct Answer is:
B
For photon v = c
`lambda_(p) = c/v =(3xx10^(8))/(6xx10^(14))=1/2xx10^(-6)m`
For electron
`lambda_(e) =10^(-3) xx lambda_(p) = (10^(-9))/2 m `
`lambda = h/p ,p mv`
`v = h/(lambdam)=(6.63xx10^(-34))/(1/2xx10^(-9)xx9.1xx10^(-31))=1.45xx10^(6)`m/s.
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