When X-rays of wavelength `0-5Å` pass through 7 mm thick aluminium sheet, then their intensity reduces to one fourth. The coefficient of absorption of aluminium for these X-rays will be :

Options

A. `0.198mm^(-1)`
B. `0.227mm^(-1)`
C. `0.752mm^(-1)`
D. `0.539mm^(-1)`

Answer

A

Explanation

Because `mu=(2*303)/(x)log_(10)((I_(0))/(I))`
`mu=(2*303 log_(10)4)/(7)=(2*303xx0*6023)/(7)=0*198 mm`