A radioactive element gets spilled over the floor of a room. Its half – life period is 30 days. If the initial velocity is ten times the permissible value, after how many days will it be safe to enter the room?

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

100days

1000days

300days

10days

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Since initial velocity is ten times the permissible value.

$∴ A_{0} = 10A$ $λ = \frac{0.693}{t_{1/2}} = \frac{0.693}{30}$

$t_{1/2} = \frac{2.303}{λ} log \frac{A_{0}}{A} = \frac{2.303}{0.693/30} log \frac{10A}{A}$

$= \frac{2.303 × 30}{0.693} × log 10 = 100 days$

Watch 3-min video & get full concept clarity

JEE

NEET

Foundation JEE

Foundation NEET

CBSE