X-rays of wavelength 0.14.nm are scattered from a block of carbon .What will be the wavelength of X-rays sacatted at `90^(@)`?

Options

A. 0.140 nm
B. 0.142 nm
C. 0.144 nm
D. 0.146 nm

Answer

B

Explanation

Wavelength ,`lamda=0.140xx10^(-9)`(Given)
Scattering angle =`90^(@)`
The expression for wavelength of X-rays is given as
`lamda'=lamda+(h)/(m_(e)c)(1-cost0)`
Where
`(h=6.663xx10^(-34),m_(e)=9.1xx10^(-31),c=3xx10^(8))`
`implies lamda=0.140xx10^(-9)+(6.63xx10^(-34))/((9.1xx10^(-31))(3xx10^(8))`
" `="0.140xx10
^(-9)+2.4xx10^(-12)`
`therefore lamda=0.142nm`