The counting rate observed from a radioactive source at $$t=0$$ was $$1600$$ counts per second and at $$t=8s$$ it was $$100$$ counts per second. The counting rate observed as counts per second at $$t=4sec$$ will be

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Infinity Learn · Accepted Answer

Activity, $$A=A02n$$      here n $$=tTh$$ ⇒$$100=16002n$$ ⇒$$n=4$$ ⇒$$tTh=4$$ ⇒Th $$=$$ $$t4=84=$$ $$2$$ $$sec$$ Since t $$=$$ $$8$$ $$sec$$, it means that in $$8$$ $$sec$$ there are $$4$$ half lives.  So, after t $$=$$ $$4$$ $$sec$$, there are $$2$$ half lives ∴$$n=tTh=42=2$$ Now, activity $$=A=A02n=160022=400$$ cps

The counting rate observed from a radioactive source at t=0 was 1600 counts per second and at t=8s it was 100 counts per second. The counting rate observed as counts per second at t=4sec will be

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