A freshly prepared radioactive source of half life 2 hours 30 minutes emits radiation which is 64 times the permissible safe level. The minimum time, after which it would be possible to work safely with source, will be hours.

Question

A freshly prepared radioactive source of half life 2 hours 30 minutes emits radiation which is 64 times the permissible safe level. The minimum time, after which it would be possible to work safely with source, will be hours. (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

A = A 0 × 2- t / T ( A 0/64)= A 0 × 2- t / T ∴ t =6 T =6 × 2 ⋅ 5=15 hours

Q. A freshly prepared radioactive source of half life 2 hours 30 minutes emits radiation which is 64 times the permissible safe level. The minimum time, after which it would be possible to work safely with source, will be ___hours.

$A = A_{0} \times 2^{- t / T}$
$\frac{A _{0}}{64} = A_{0} \times 2^{- t / T}$
$∴ t = 6 T = 6 \times 2 \cdot 5 = 15$ hours

Q. A freshly prepared radioactive source of half life 2 hours 30 minutes emits radiation which is 64 times the permissible safe level. The minimum time, after which it would be possible to work safely with source, will be ___hours.

A=A0​×2−t/T 64A0​​=A0​×2−t/T ∴t=6T=6×2⋅5=15 hours

$A = A_{0} \times 2^{- t / T}$
$\frac{A _{0}}{64} = A_{0} \times 2^{- t / T}$
$∴ t = 6 T = 6 \times 2 \cdot 5 = 15$ hours