Student Login

Home›Chapters›Nuclear Physics PYQs›Law of Radioactive Decay›Question 104

NEET 2010 (AIPMT, Mains) · Law of Radioactive Decay

Law of Radioactive Decay question from NEET 2010 (AIPMT, Mains)

Q104NEET 2010 · AIPMT · MAINSMedium

Law of Radioactive Decay

The decay constant of a radio isotope is $\lambda$ . If A1 and A2 are its activities at times t1 and t2 respectively, the number of nuclei which have decayed during the time (t1 $-$ t2)

Show answer and solution

Answer: (c)

$A = \lambda N$ , so $N_1 = \frac{A_1}{\lambda}$ and $N_2 = \frac{A_2}{\lambda}$ .
Nuclei decayed $= N_1 - N_2 = \frac{A_1 - A_2}{\lambda}$ .
So the answer is (c) $(A_1 - A_2)/\lambda$ .

Report a mistake

More questions on Law of Radioactive Decay

The activity of a radioactive sample is measured as N0 counts per minute at t = 0 and…NEET 2010 (AIPMT, Prelims)
Two radioactive materials X1 and X2 have decay constants 5λ and λ respectively. If…NEET 2008 (AIPMT)
Two radioactive substances A and B have decay constants 5 λ and λ respectively. At t = 0…NEET 2007 (AIPMT)
The half-life period of a radioactive element X is same as the mean life time of another…JEE Main 2007 (AIEEE)
In a radioactive material the activity at time t1 is R1 and at a later time t2, it is R2…NEET 2006 (AIPMT)
The 'rad' is the correct unit used to report the measurement ofJEE Main 2006 (AIEEE)
Starting with a sample of pure ⁶⁶Cu, 7/8 of it decays into Zn in 15 minutes. The…JEE Main 2005 (AIEEE)
The half life of radian is about 1600 years. Of 100 g of radium existing now, 25 g will…NEET 2004 (AIPMT)