Question

If the half life is found to be 100 msec, what is the decay constant?

(a) 693 per second

(b) 24948 per hour

(c) 0.1155 per minute

(d) 59875.2 per day

The question was asked in class test.

Asked question is from Diathermy, Measurement of Radiation, Dose and its Calculations topic in chapter Radiation Therapy of Clinical Science

Answer 1

Correct option is (b) 24948 per hour

Explanation: Half life is and decay constant are related by t ^1/2 = ln2/λ

t ^1/2 = 0.693/λ

Since the half life is given in seconds, appropriate conversions are used for hours, minutes and day. By this, we get:

λ = 0.693*3600/t^1/2 = 249480 per hour.