Home
Class 12
PHYSICS
The activity of a sample of a radioactiv...

The activity of a sample of a radioactive material is `A_(1)` at time `t_(1)` and `A_(2)` at time `t_(2) , ( t_(2) gt t_(1))` . Its mean life is T. Then ______ .

A

`A_(1)t_(1) = A_(2)t_(2)`

B

`(A_(1)-A_(2))/(t_(2)-t_(1))`= Constant

C

`A_(2) = A_(1) e^((t_(1)-t_(2))//T)`

D

`A_(2)=A_(1) e^(t_(1)/t_(2)T)`

Text Solution

Verified by Experts

The correct Answer is:
C
`A_(1)=A_(0)e^(-lambdat1)`
`A_(2)=A_(0)e^(-lambdat2)`
`:. " "(A_(2))/(A_(1))=(e^(-lambdat_(2)))/(e^(-lambdat_(1)))`
`e^(lambda(t_(1)-t_(2)))`
`implies " "(A_(2))/(A_(1))=e^((t_(1)-t_(2))/(T))`
`(becauselambda=(1)/(T))`
`implies " "A_(2)= A_(1)e^((t_(1)-t_(2))//T)`
Promotional Banner

Similar Questions

Explore conceptually related problems

Determine the tension T_(1) and T_(2) in the strings

If the sequence t_(1), t_(2), t_(3), … are in A.P. then the sequence t_(6), t_(12), t_(18),… is

If G.P if t_(1)=(1)/(5) and t_(2)=(1)/(25) then the common ratio is ___.

The activity of a radioactive sample is measured as N_0 counts per minute at t=0 and N_0//e counts per minutes at t=5 minutes. The time (in minutes ) at which the activety reduces to half its value is :

If t_(1) and t_(2) are the extremities of any focal chord of y^(2) = 4ax " then " t_(1)t_(2) is _____

The point of intersection of the tangent at t_(1)=t and t_(2)=3t to the parabola y^(2)=8x is . . .