The counting rate observed from a radioactive source at t=0 second was 1600 counts per second and at t=8 seconds it was 100 counts per second. The counting rate observed, as counts per second at t=6 seconds, willbe

Options

A. 400
B. 300
C. 200
D. 150

Answer

C

Explanation

`R= R_(0) ((1)/(2))^((t)/(T_(1//2)))`
`rArr 100= 1600 ((1)/(2))^((8)/(T_(1//2))) rArr T_(1//2)= 2` sec
at t= 6 sec
`R.= 1600 ((1)/(2))^((6)/(2))= 200` counts/sec