Photoelectric EffectHard

Question

A B C
t = 0    N0       0            0         
t          N1       N2          N3
In the above radioactive decay C is stable nucleus. Then:   

Options

A.rate of decay of A will first increase and then decrease
B.number of nuclei of B will first increase and then decrease
C.if λ2 > λ1, then activity of B will always be higher than activity of A
D.if λ2 > λ1, then number of nucleus of C will always be less than number of nucleus of B.

Solution

Rate of decay of A keeps on decreasing continuously because concentration of A decreases with time. ⇒ A is false
Initial rate of production of B is λ1N0 and rate of decay is zero. With time, as the number of B atom increase, the rate of its production decrease and its rate of decay increases. Thus the number of nuclei of B will first increase and then decrease.  ⇒ B is the correct choice
The initial activity of B is zero whereas initial activity of A is λ1N0 ⇒ C is false.
As time t → ∞ : NA = 0, NB = 0 and NC = N0. ⇒ D is false

Create a free account to view solution

View Solution Free
Topic: Photoelectric Effect·Practice all Photoelectric Effect questions

More Photoelectric Effect Questions