Question : A freshly prepared radioactive source of half life 2 hr 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
A. 6 hr
B. 12 hr
C. 24 hr
D. 128 hr
Answer:B
Question : A freshly prepared radioactive source of half life 2 hr 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
A. 6 hr B. 12 hr C. 24 hr D. 128 hr