Photoelectric EffectHard
Question
A freshly prepared radioactive source of half-life 2 h emits radiation of intensity which is 64 times the permissible safe level. The minimum time after which it would be possible to work safely with this source is -
Options
A.6 h
B.12 h
C.24 h
D.128 h
Solution
64 = 26
After 6 half lives activity will become = 1/64
Hence required time = 6 × 2h = 12h.
After 6 half lives activity will become = 1/64
Hence required time = 6 × 2h = 12h.
Create a free account to view solution
View Solution FreeMore Photoelectric Effect Questions
What is the momentum (in kg m/s) of a photon having frequency 1.5 × 1013 Hz :-...If X-rays is passed through from strong magnetic field, then X-rays :-...At time t = 0, some radioactive gas is injected into a sealed vessel. At time T, some more of the same gas is injected i...The work function for aluminium surface is 4.2 eV and that for sodium surface is 2.0 ev. The two metals were illuminated...In a hypothetical atom, if transition from n = 4 to n = 3 produces visible light then the possible transition to obtain ...