R1=R0e−λ4 and R2=R0e−λλ2 ⇒R,R1⇒R1=e−λλ2e−λλ1=e−λ(t1−t2)=R2e−λ(t1−t2)
In a radioactive material the activity at time t_1 is R_1 and at a later time t_2, it is R_2. If the decay constant of the material is λ, then:
NEET UG 2006 — Physics Modern Physics
2006mcqmedium
In a radioactive material the activity at time t1 is R1 and at a later time t2, it is R2. If the decay constant of the material is λ, then:
Official previous-year question
Held on 30 Apr 2006 · Verified 9 Jul 2026.
Options
- A
R1=R2
- B
R1=R2e−λ(t1−t2)
- C
R1=R2eλ(t1−t2)
- D
R1=R2(t2/t1)
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