Question

 Activities of three radioactive substances A, B and C are represented by the curves A, B and C, in the figure. Then their half-lives  

T_{\(\frac{1}{2}\)} (A) : T_{\(\frac{1}{2}\)} (B) : T_{\(\frac{1}{2}\)}(C) are in the ratio

(1) 2 : 1 : 3 

(2) 4 : 3 : 1 

(3) 2 : 1 : 1 

(4) 3 : 2 : 1

Answer 1

Correct answer is (1) 2 : 1 : 3

R =λN₀e^–λt 

⇒ lnR = lnλN₀ – λt  

⇒Slope of curves = –λ