TG EAMCET 3 May 2025 Shift 1 Paper

The safe level of radiation is 32 times less than what the material gives off now.
Each time a half-life ( 2.5 hours) passes, the radiation becomes half of what it was before.
We can write this as: (‌

1

2

)n=‌

1

32

where n is the number of half-lives needed until the radiation is safe.
We know ‌

1

32

=(‌

1

2

)5. So, n=5.
This means it takes 5 half-lives to reach a safe level.
Calculating total time:
‌

t

T1∕2

=5⇒t=5×T1∕2
Each half-life is 2.5 hours, so total time is:
t=5×2.5=12.5 hours