At a given instant, say t = 0, two radioactive substance A and B have equal activities. The ratio of their activities after time t itself decays with time t as e^{−34 }.^{ } If the halflife of A is m_{2 }, the halflife of B is
a. 

b. 
2ln2 
c. 

d. 
4ln2 
At a given instant, say t = 0, two radioactive substance A and B have equal activities. The ratio of their activities after time t itself decays with time t as e^{−34 }.^{ } If the halflife of A is m_{2 }, the halflife of B is
a. 

b. 
2ln2 
c. 

d. 
4ln2 
Half life of A = ln2
t_{1/2 = } _{ }
λ_{A }= 1
at t = 0 R_{A }= R_{B }
N_{A }e^{−λAT} = N_{B }e^{−λBT}
N_{A }= N_{B }at t = 0
at t = t _{ }=
= e^{−t }
λ_{B}−λ_{A} = 3
λ_{B}= 3 + λ_{A} = 4
t_{1/2 }=_{ } _{ }=_{ }