An experimenter measures 9924 counts during one hour from a radioactive sample. From this number the counting rate of the sample can be estimated with a standard deviation of most nearly
A. 100
B. 200
C. 300
D. 400
E. 500
(GR8677 #40)
Solution:
Radioactive decay can be described by Poisson Distribution.
Poisson Distribution (PD):
Probability distribution of discrete events over an interval (time. distance, etc)
In PD, Standard Deviation, σ = √μ (see Notes)
μ = expected number of events
Given: μ = 9924 ≈ 10000
σ = √10000 = 100
Answer: A
Notes: (click to enlarge)
No comments :
Post a Comment