Q. A radioactive material has a half life of 10 days. What fraction of the material would remain after 30 days
A) 0.5
B) 0.25
C) 0.125
D) 0.33
Explanation
(c) $N = N_{0}\left( \frac{1}{2} \right)^{\frac{t}{T_{1/2}}} \Rightarrow \frac{N}{N_{0}} = \left( \frac{1}{2} \right)^{\frac{30}{10}} = \frac{1}{8} = 0.125$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.