The power obtained in a reactor using `U^235` disintegration is `100 kW`. The mas decay of `U^235` per hour is

Options

A. 10 microgram
B. 20 microgram
C. 40 microgram
D. 1 microgram

Answer

C

Explanation

According to mass-energy relation
`E=mc^(2) or m=E//c^(2)`
Mass decay per second `=(dm)/(dt)=1/(c^(2)) (dE)/(dt)`
`=1/(c^(2))` (Power inn watt)
`=(1xx(1000xx10^(3)W))/((3xx10^(8)m//s)^(2))=1/(9xx10^(10))kg//s`
Mass decay per hour `=(dm)/(dt) xx60xx60`
`=1/(9xx10^(10))xx60xx60=4xx10^(-8)kg=40 mug`