Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
2.4k views
in Physics by (44.7k points)

A radioactive substance decays to (1 / 16)th of its initial activity in 40 days. the half life of the radioactive substance expressed in day is 

(A) 20 

(B) 5 

(C) 10 

(D) 4

1 Answer

+1 vote
by (69.7k points)
selected by
 
Best answer

The correct option is (C) 10.

Explanation:

In t = 40 days, substance decays to (1 / 16) of original i.e. fraction left is  (1 / 16).

If half life is T(1/2) then fraction left = (N / N0) = (1 / 2)[t / {T(1/2)}]

(1 / 16) = (1 / 2)[(40) / {T(1/2)}]

(1 / 2)4  = (1 / 2)[(40) / {T(1/2)}]

4 = [(40) / T(1/2)]

T(1/2) = (40 / 4) = 10 days. 

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...