| ⇦ | 
| ⇨ |
The half life of radium is about 1600 year. Of 100 gram of radium existing now, 25g will remain unchanged after
Options
(a) 4800 year
(b) 6400 year
(c) 2400 year
(d) 3200 year
Correct Answer:
3200 year
Explanation:
100 gram at beginning, I = 0
25 gram remains undecayed.
N / N₀ = (1 / 2)ⁿ ⇒ 25 / 100 = (1 / 2)ⁿ
⇒ 1 / 4 = (1 / 2)ⁿ
Therefore, n = 2
Time = n × T
= 2 × 1600
= 3200 years.
Related Questions: - A and B are two metals with threshold frequencies 1.8 x 10¹⁴ Hz and 2.2 x 10¹⁴ Hz.
- If a full wave rectifier circuit is operating from 50 Hz mains, the fundamental
- An object is attached to the bottom of a light vertical spring and set vibrating.
- The earth radiates in the infrared region of the spectrum. The spectrum is correctly
- A body A experiences perfectly elastic collision with a stationary body B
Topics: Radioactivity
(83)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- A and B are two metals with threshold frequencies 1.8 x 10¹⁴ Hz and 2.2 x 10¹⁴ Hz.
- If a full wave rectifier circuit is operating from 50 Hz mains, the fundamental
- An object is attached to the bottom of a light vertical spring and set vibrating.
- The earth radiates in the infrared region of the spectrum. The spectrum is correctly
- A body A experiences perfectly elastic collision with a stationary body B
Topics: Radioactivity (83)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
18000+ students are using NEETLab to improve their score. What about you?
Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.
Share this page with your friends
Leave a Reply